LIQUI MOLY

LIQUI MOLY Lead Substitute 250ml – Classic Porsche Unleaded Petrol Additive

LIQUI MOLY Lead Substitute is a specialist petrol additive developed to protect older engines originally designed to operate on leaded fuel. Its protective formula lubricates non-hardened valve seats, reducing wear and helping maintain engine compression when using modern unleaded petrol.

Fits:

• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

Ideal for appropriate classic Porsche engines, it also helps clean intake valves, combustion chambers and fuel preparation systems, supporting reliable engine operation and long-term protection.

What Does LIQUI MOLY Lead Substitute Do?

Lead Substitute provides protective lubrication for valve seats originally designed to benefit from leaded petrol. It helps prevent valve seat recession, reduces cylinder head wear and maintains compression in older petrol engines.

Why Do Classic Engines Need Lead Substitute?

Some older petrol engines were manufactured with non-hardened valve seats that relied on the protective properties of leaded fuel.

Using unleaded petrol without suitable protection can increase valve seat wear, potentially causing reduced compression, poor performance and eventual cylinder head damage.

When Should It Be Used?

Lead Substitute should be used when operating a classic petrol engine originally requiring leaded fuel and fitted with valve seats that have not been upgraded for unleaded petrol.

For continuous protection, LIQUI MOLY recommends adding the correct quantity at every refuelling.

Many Porsche engines already have suitable valve seat materials or have been upgraded during restoration. Check the original engine specification and cylinder head condition before use. Lead Substitute is generally unnecessary for engines designed to operate on unleaded petrol.

The product does not increase the octane rating of petrol and is not a replacement for the correct fuel grade.

Key Features

• Protects non-hardened valve seats against premature wear.
• Helps prevent valve seat recession.
• Supports consistent engine compression.
• Reduces the risk of cylinder head damage.
• Helps clean intake valves and combustion chambers.
• Designed for classic engines originally requiring leaded petrol.
• Compatible with retrofitted catalytic converters.
• Contains no organometallic compounds.
• Convenient measuring dispenser for accurate dosing.

Application Instructions

• Add Lead Substitute directly to the petrol fuel tank before refuelling.
• Use 25ml for every 25 litres of unleaded petrol.
• Maintain the recommended mixing ratio of 1:1,000.
• One 250ml container treats up to 250 litres of petrol.
• Repeat at every refuelling where continued valve seat protection is required.

Important: Avoid underdosing or overdosing. Always use the correct petrol octane rating recommended for the engine.

Product Category Description – Classic Porsche Lead Replacement & Fuel Additives

LIQUI MOLY Lead Substitute provides essential valve seat protection for classic Porsche petrol engines originally designed to operate on leaded fuel. Its specialised formula helps reduce valve seat wear, maintain compression and protect older cylinder heads when using modern unleaded petrol.

Suitable for consideration in classic Porsche 356, 911, 912, 914 and other early petrol engines requiring lead replacement protection, it offers a convenient maintenance solution for original, unrestored and period-correct engines.

LIQUI MOLY Catalytic-System Clean - 300ml

LIQUI MOLY Catalytic-System Clean is a petrol fuel additive designed to help protect catalytic converters from soot contamination while cleaning fuel injectors, intake valves and combustion chambers.

Not suitable for diesel engines.

Its combustion-improving formula helps reduce harmful exhaust emissions, improve fuel efficiency and maintain smooth engine performance. It also provides corrosion protection within the fuel system.

Suitable for naturally aspirated and turbocharged petrol engines equipped with catalytic converters.

What Does LIQUI MOLY Catalytic-System Clean Do?

Catalytic-System Clean helps remove deposits from the fuel injection and combustion systems while reducing soot formation that can affect catalytic converter efficiency.

By promoting cleaner combustion, it helps reduce exhaust pollutants and supports efficient engine operation.

Why Do Catalytic Converters Become Contaminated?

Over time, incomplete combustion, fuel system deposits and excessive soot production can contribute to catalytic converter contamination.

These deposits may reduce exhaust system efficiency, increase emissions and contribute to poor engine performance.

Catalytic-System Clean helps limit soot contamination through improved combustion and fuel system cleaning.

When Should It Be Used?

The additive is recommended as a preventative maintenance treatment, particularly for petrol engines experiencing frequent short journeys, stop-start driving or suspected fuel system contamination.

It can be used during regular refuelling to help maintain efficient combustion and catalytic converter performance.

It is not a repair for physically damaged or severely blocked catalytic converters.

Key Features

• Helps protect catalytic converters against soot contamination.
• Cleans fuel injectors and combustion chambers.
• Helps remove deposits from the fuel preparation system.
• Supports cleaner and more efficient combustion.
• Helps reduce harmful exhaust emissions.
• Can improve fuel economy through improved combustion.
• Provides corrosion protection within the fuel system.
• Tested for use with turbochargers and catalytic converters.
• Provides a cleaning effect lasting up to 2,000km.

Application Instructions

• Pour the additive directly into the petrol fuel tank.
• One 300ml can treats up to 70 litres of petrol.
• The additive mixes automatically with the fuel.
• Can be added at any time as a preventative treatment.
• Cleaning and protective effects remain for up to 2,000km.

Important: LIQUI MOLY states that manganese oxide deposits inside catalytic converters cannot be removed using this product.

Product Category Description – Porsche Catalytic Converter & Fuel System Cleaners

LIQUI MOLY Catalytic-System Clean provides an effective preventative maintenance solution for Porsche petrol engines equipped with catalytic converters. Its cleaning formula helps maintain fuel injection system cleanliness, improve combustion efficiency and reduce soot contamination.

LIQUI MOLY Pro-Line Throttle Valve Cleaner 400ml – Throttle Body & Intake Cleaner

LIQUI MOLY Pro-Line Throttle Valve Cleaner is a professional cleaning spray designed to remove oil, dirt, resin and sticky deposits from petrol engine throttle bodies and intake systems.

Its fast-acting solvent formula helps restore smooth throttle valve movement, improve engine reliability and maintain efficient airflow. The cleaner can be applied without completely dismantling the throttle body assembly.

What Does LIQUI MOLY Pro-Line Throttle Valve Cleaner Do?

The cleaner dissolves accumulated contamination around the throttle butterfly, intake passages and associated openings. Removing these deposits helps maintain correct throttle operation, stable engine idling and consistent engine response.

Why Do Throttle Valves Become Dirty?

Over time, oil vapour from the crankcase ventilation system, dirt and combustion-related residues can accumulate inside the throttle body.

These deposits can restrict airflow or interfere with throttle butterfly movement, potentially causing rough idling, hesitation, reduced throttle response and increased fuel consumption.

When Should It Be Used?

Throttle valve cleaning is recommended when experiencing uneven idling, throttle hesitation or visible contamination around the throttle body.

It can also be carried out during routine intake system maintenance, particularly on older or higher-mileage Porsche petrol engines.

Key Features

• Removes oil, resin, dirt and sticky deposits.
• Cleans throttle butterflies and intake passages.
• Helps restore smooth throttle valve operation.
• Supports stable engine idling and throttle response.
• Helps maintain efficient airflow and fuel consumption.
• Fast-acting solvent cleaning formula.
• Cleaning possible without complete throttle body removal.
• Tested for use with catalytic converters.
• Convenient 400ml aerosol with spray probe.

Application Instructions

• Gain direct access to the throttle valve using the appropriate service procedure.
• Start the engine and maintain a minimum speed of 2,000rpm.
• Apply the cleaner across the throttle valve in short 2–3 second intervals using the spray probe.
• Reduce spraying if engine speed fluctuates excessively.
• Allow the engine to run for approximately 20 seconds at a minimum of 2,000rpm after cleaning to clear remaining residue.

Avoid contact with the mass airflow sensor and painted surfaces. Some vehicles may require diagnostic fault-code clearing or throttle adaptation following cleaning.

Important: This is a professional workshop cleaning product. Follow LIQUI MOLY's instructions and the Porsche-specific service procedure, particularly for electronically controlled throttle bodies and turbocharged intake systems.

Product Category Description – Porsche Throttle Body & Intake System Cleaners

LIQUI MOLY Pro-Line Throttle Valve Cleaner provides an effective cleaning solution for Porsche petrol engine throttle bodies and intake systems, helping remove accumulated contamination and restore efficient throttle operation.

Suitable for use on compatible Porsche 911, 924, 944, 968, 928, Boxster, Cayman, Cayenne, Macan and Panamera petrol engines, it helps maintain smooth idling, consistent throttle response and reliable engine performance.

LIQUI MOLY Pro-Line Direct Injection Cleaner - 120ml

LIQUI MOLY Pro-Line Direct Injection Cleaner is an advanced petrol fuel additive designed to remove deposits from fuel injectors, combustion chambers and piston surfaces. Its powerful polyetheramine (PEA) formula helps restore efficient fuel delivery, improve combustion and maintain smooth engine performance.

Fits:

• Porsche Boxster 987 MKII 2009-12
• Porsche Boxster 981 2012-16
• Porsche Boxster 718 2017>>
• Porsche 997 MKII 2009-12
• Porsche 991.1 2012-16
• Porsche 991.2 2016-19
• Porsche 992.1 2019-24
• Porsche 992.2 2024>>
• Porsche Cayman 987C MKII 2009-12
• Porsche Cayman 981 2013-16
• Porsche Cayman 718
• Porsche 957 Cayenne 2007-10
• Porsche 958 Cayenne 2010-17
• Porsche 9YA Cayenne 2018-23
• Porsche 9YA.2 Cayenne 2023>>
• Porsche 970.1 Panamera 2009-13
• Porsche 971.1 Panamera 2017-20
• Porsche 971.2 Panamera 2021-23
• Porsche 976 Panamera 2023>>
• Porsche 95B.1 Macan 2014-18
• Porsche 95B.2 Macan 2019-21
• Porsche 95B.3 Macan 2022>>

Developed particularly for modern direct injection petrol engines, it also helps reduce the risk of low-speed pre-ignition (LSPI), which can cause serious engine damage.

What Does LIQUI MOLY Pro-Line Direct Injection Cleaner Do?

The additive removes deposits from fuel injectors and combustion chambers, helping maintain correct fuel spray patterns and efficient combustion. This can improve engine responsiveness, reduce fuel consumption and support smoother running.

Why Do Fuel Injectors Become Contaminated?

Fuel injectors are exposed to high temperatures and combustion deposits. Over time, carbon and other contaminants can accumulate around injector nozzles, disrupting fuel delivery and potentially causing rough running, increased fuel consumption or reduced engine performance.

When Should It Be Used?

LIQUI MOLY recommends the additive for periodic fuel system maintenance, particularly in direct injection engines. It can help address deposit-related performance issues and maintain injector cleanliness.

For best results, treatments should be spaced at least 5,000km apart.

Not suitable for diesel engines.

Key Features

• Advanced PEA cleaning technology.
• Removes deposits from petrol fuel injectors.
• Cleans combustion chambers and piston surfaces.
• Helps restore efficient fuel spray patterns.
• Reduces the risk of low-speed pre-ignition (LSPI).
• Supports smoother engine operation and fuel efficiency.
• Suitable for direct and manifold petrol injection systems.
• Ideal for periodic fuel system maintenance.

Application Instructions

• Add the contents directly to the petrol fuel tank.
• One 120ml can treats 30–50 litres of petrol.
• The additive mixes automatically with the fuel.
• Repeat no sooner than every 5,000km for ongoing maintenance.

Follow vehicle manufacturer recommendations where these differ from the standard dosage.

Product Category Description – Porsche Direct Injection & Fuel System Cleaners

LIQUI MOLY Pro-Line Direct Injection Cleaner provides an effective fuel system cleaning solution for Porsche petrol engines, helping remove injector deposits and maintain efficient combustion.

Particularly suited to modern direct fuel injection Porsche engines, including the 997.2, 991, 992, Boxster, Cayman, 718, Cayenne, Macan and Panamera, it helps maintain injector performance and reduce deposit-related running problems.

LIQUI MOLY Speed Tec Gasoline Petrol Performance Additive – 250ml

LIQUI MOLY Speed Tec Gasoline is a high-performance petrol additive designed to improve throttle response, acceleration and engine smoothness. Its advanced formula optimises combustion, helping the engine respond more efficiently during acceleration and everyday driving.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche Boxster 987 2.7L 2005-08/08
• Porsche Boxster 987 S 3.2/3.4L 2005-08/08
• Porsche Boxster 987 MKII 2.9L 2009-12
• Porsche Boxster S 987 MKII 3.4L 2009-12
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche 997 MK1 Carrera 2 3.6L 2005-08
• Porsche 997 MK1 Carrera 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche Cayman 2.7L 987C 2006-08
• Porsche Cayman S 3.4L 987C 2005-08
• Porsche Cayman 2.9L 987C MKII 2009-12
• Porsche Cayman S / R 3.4L 987C MKII 2009-12
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-92
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

Suitable for naturally aspirated and turbocharged petrol engines, it can help improve drivability without increasing the fuel's octane rating.

What Does LIQUI MOLY Speed Tec Gasoline Do?

Speed Tec Gasoline improves fuel combustion characteristics, helping the engine respond more quickly to throttle inputs. It promotes smoother acceleration, easier starting and improved performance, particularly under partial engine load.

Why Use a Petrol Performance Additive?

Petrol engines can experience less responsive acceleration or uneven running due to combustion inefficiencies. Speed Tec helps optimise fuel combustion to improve engine responsiveness and driving smoothness.

When Should It Be Used?

Speed Tec Gasoline can be added during routine refuelling or when improved throttle response and smoother engine operation are desired. LIQUI MOLY also recommends it for continued use with regular refuelling.

Key Features

• Improves acceleration and throttle response.
• Optimises combustion and engine performance.
• Helps promote smoother engine running.
• Supports easier engine starting.
• Suitable for naturally aspirated and turbocharged petrol engines.
• Tested for compatibility with catalytic converters.
• Does not increase fuel octane rating.
• Contains no organometallic compounds.
• Suitable for regular use during refuelling.

Application Instructions

• Pour the additive directly into the petrol fuel tank.
• One 250ml can treats up to 70 litres of petrol.
• The additive mixes automatically with the fuel.
• Suitable for repeated use during regular refuelling.

No additional engine modifications are required.

Product Category Description – Porsche Petrol Fuel Additives

LIQUI MOLY Speed Tec Gasoline provides a convenient solution for improving petrol engine responsiveness and combustion efficiency across a wide range of Porsche models.

Whether maintaining a classic air-cooled Porsche 911, a Porsche 944, 968, Boxster, Cayman or a modern turbocharged Porsche, Speed Tec Gasoline helps promote smoother acceleration and improved throttle response.

LIQUI MOLY Pro-Line Engine Flush – Porsche Engine Oil System Cleaner

LIQUI MOLY Pro-Line Engine Flush is a professional engine cleaning treatment designed to remove sludge, oil deposits and contamination from internal engine components before an oil change.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche Boxster 987 2.7L 2005-08/08
• Porsche Boxster 987 S 3.2/3.4L 2005-08/08
• Porsche Boxster 987 MKII 2.9L 2009-12
• Porsche Boxster S 987 MKII 3.4L 2009-12
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche 997 MK1 Carrera 2 3.6L 2005-08
• Porsche 997 MK1 Carrera 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche Cayman 2.7L 987C 2006-08
• Porsche Cayman S 3.4L 987C 2005-08
• Porsche Cayman 2.9L 987C MKII 2009-12
• Porsche Cayman S / R 3.4L 987C MKII 2009-12
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-92
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

Its fast-acting formula cleans oil passages, bearings and piston ring areas, helping improve engine lubrication, reduce operating noise and restore smoother engine performance.

Suitable for petrol and diesel engines, including turbocharged applications, it is compatible with commercially available engine oils and has been tested for use with catalytic converters and particulate filters.

What Does LIQUI MOLY Pro-Line Engine Flush Do?

The treatment dissolves accumulated deposits and contaminants within the engine's lubrication system, allowing them to be removed with the old engine oil. This helps maintain clear oil passages and supports efficient lubrication of moving components.

Why Do Engines Need Flushing?

Over time, engine oil can accumulate sludge, carbon-related deposits and other contaminants, particularly where oil changes have been delayed or the engine has experienced demanding operating conditions.

These deposits can restrict oil circulation, contribute to engine noise and interfere with oil-operated components.

When Should It Be Used?

Pro-Line Engine Flush is used immediately before an engine oil and filter change. It can be particularly beneficial when servicing an engine with suspected oil deposits, poor maintenance history or contamination-related running issues.

Key Features

• Removes sludge and deposits from internal engine components.
• Cleans oil passages, bearings and piston ring areas.
• Helps reduce engine noise and oil consumption.
• Supports improved compression and engine reliability.
• Suitable for petrol, diesel and turbocharged engines.
• Gentle on common engine sealing materials.
• Fast-acting treatment before an oil change.

Application Instructions

• Warm the engine to normal operating temperature.
• Add Pro-Line Engine Flush to the existing engine oil.
• Allow the engine to idle for 10–15 minutes, depending on contamination.
• Drain the old oil and replace the oil filter.
• Refill with the correct Porsche-approved engine oil.

Do not drive the vehicle during the flushing process.

LIQUI MOLY specifies 500ml for engines containing up to 5 litres of oil. Engines with larger capacities require the appropriate quantity of product.

Product Category Description – Porsche Engine Flush & Oil System Cleaners

LIQUI MOLY Pro-Line Engine Flush provides an effective cleaning solution for Porsche engine oil systems, helping remove accumulated sludge and deposits before routine oil servicing.

Whether maintaining a classic air-cooled Porsche 911, a Porsche 944, 968, Boxster, Cayman or modern turbocharged Porsche engine, this professional cleaning treatment helps maintain clean lubrication passages and efficient engine operation where its use is appropriate.

LIQUI MOLY Oil Additive MoS2 Engine Protection – 125ml

LIQUI MOLY Oil Additive is a molybdenum disulphide (MoS2) engine oil treatment designed to reduce friction, minimise engine wear and improve running smoothness. It forms a protective lubricating film on moving metal surfaces, providing additional protection during engine operation.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche Boxster 987 2.7L 2005-08/08
• Porsche Boxster 987 S 3.2/3.4L 2005-08/08
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche 997 MK1 Carrera 2 3.6L 2005-08
• Porsche 997 MK1 Carrera 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche Cayman 2.7L 987C 2006-08
• Porsche Cayman S 3.4L 987C 2005-08
• Porsche Cayman 2.9L 987C MKII 2009-12
• Porsche Cayman S / R 3.4L 987C MKII 2009-12
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-91
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

Suitable for petrol and diesel engines, including turbocharged applications, it mixes with commercially available engine oils and is compatible with oil filters and catalytic converters.

What Does LIQUI MOLY Oil Additive Do?

The MoS2 additive provides an additional protective layer between moving engine components, helping reduce metal-to-metal contact, friction and operating wear. It can also contribute to smoother engine operation and reduced oil and fuel consumption.

Why Use an Engine Oil Additive?

Engine components experience friction and wear during normal operation, particularly during cold starts and under high loads. LIQUI MOLY Oil Additive supplements engine oil lubrication to help protect internal components and reduce mechanical wear.

When Should It Be Used?

The additive can be introduced during a routine engine oil change or added to existing engine oil at any time. It is particularly relevant for owners looking for additional lubrication protection in older or higher-mileage engines.

Key Features

• Contains MoS2 for additional lubrication protection.
• Helps reduce friction and engine wear.
• Promotes smoother and quieter engine operation.
• May help reduce oil and fuel consumption.
• Suitable for petrol and turbocharged engines.
• Compatible with commercially available engine oils and oil filters.
• 125ml metal container.

Application Instructions

Shake well before use and add directly to the engine oil.

Recommended concentration: 3–5% of total engine oil volume, with LIQUI MOLY's standard application instruction specifying 50ml per litre of oil.

A 125ml can provides a 5% treatment for approximately 2.5 litres of engine oil. Larger Porsche engine oil capacities will require additional additive to achieve the recommended concentration.

Product Category Description – Porsche Engine Oil Additives

LIQUI MOLY engine oil additives offer additional lubrication protection for Porsche engines. Whether maintaining a classic air-cooled Porsche 911, a 944, 968 or a later Boxster, Cayman MoS2 oil treatments are designed to help reduce engine friction and protect moving components where their use is permitted.

Available from Design911, LIQUI MOLY Oil Additive 125ml offers a convenient solution for supplementary engine lubrication and wear protection.

LIQUI MOLY Molygen Motor Protect – 500ml

LIQUI MOLY Molygen Motor Protect is a synthetic engine oil additive designed to reduce friction and wear in modern petrol and diesel engines.

Fits:

• Porsche 986 Boxster
• Porsche 987 Boxster
• Porsche 981 Boxster 
• Porsche 718 Boxster
• Porsche 987 Cayman
• Porsche 981 Cayman
• Porsche 718 Cayman
• Porsche 996
• Porsche 997
• Porsche 991
• Porsche 992
• Porsche 970 Panamera
• Porsche 971 Panamera
• Porsche 976 Panamera
• Porsche 955 Cayenne
• Porsche 957 Cayenne
• Porsche 958 Cayenne
• Porsche 9YA Cayenne
• Porsche 95B Macan

It forms a durable, low-friction protective layer on internal engine components, helping maintain smooth operation and reduce mechanical wear. The protective effect lasts for at least 50,000km.

What Does It Do?

Molygen Motor Protect creates a low-friction protective layer on internal engine surfaces, helping reduce metal-to-metal contact, mechanical wear and friction.

Why Is It Important?

Engine components experience heat, friction and pressure during operation. Excessive friction can contribute to premature wear and reduced mechanical efficiency.

Molygen Motor Protect provides additional protection alongside the engine oil.

When Should It Be Used?

Use during or shortly after an engine oil change as part of preventative maintenance.

LIQUI MOLY recommends treatment approximately every 50,000km.

Application & Dosage

• Add directly to the engine oil.
• One 500ml container treats up to 5 litres of engine oil.
• Reduce the specified oil fill quantity by 500ml.
• Best added during or shortly after an oil change.
• Compatible with commercially available mineral and synthetic engine oils.
• Repeat approximately every 50,000km.

For Porsche engines with oil capacities exceeding 5 litres, confirm the appropriate dosage before use. Do not exceed the specified total oil fill.

Key Features

• 500ml container
• Reduces engine friction and wear
• Forms a durable low-friction protective layer
• Protection lasting at least 50,000km
• High thermal stability
• Supports smoother engine operation
• Compatible with mineral and synthetic engine oils
• Tested for particulate filters and catalytic converters
• Suitable for modern petrol and diesel engines

LIQUI MOLY Engine Wear Protection Additives for Porsche

LIQUI MOLY Molygen Motor Protect helps reduce friction between moving engine components, supporting smoother operation and long-term wear protection.

It is a potential maintenance treatment for compatible Porsche 911, Boxster, Cayman, Cayenne, Macan and Panamera petrol and diesel engines.

LIQUI MOLY E10 Additive – 150ml

LIQUI MOLY E10 Additive is a petrol fuel treatment developed to help compensate for performance losses associated with E10 petrol.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche Boxster 987 2.7L 2005-08/08
• Porsche Boxster 987 S 3.2/3.4L 2005-08/08
• Porsche Boxster 987 MKII 2.9L 2009-12
• Porsche Boxster S 987 MKII 3.4L 2009-12
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche 997 MK1 Carrera 2 3.6L 2005-08
• Porsche 997 MK1 Carrera 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche Cayman 2.7L 987C 2006-08
• Porsche Cayman S 3.4L 987C 2005-08
• Porsche Cayman 2.9L 987C MKII 2009-12
• Porsche Cayman S / R 3.4L 987C MKII 2009-12
• Porsche Cayman 2.7L 981 2013-16
• Porsche Cayman S / GTS 3.4L 981 2013-16
• Porsche Cayman GT4 3.8L 2015-16
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-91
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

Its ash-free formulation improves combustion, supports smoother acceleration and protects the fuel system against corrosion, particularly where petrol contains increased moisture.

LIQUI MOLY specifies compatibility with all petrol and additive qualities. However, using this additive does not make E10 petrol suitable for a Porsche engine or fuel system that requires E5 or another specified fuel.

Always follow Porsche's fuel recommendations, particularly for classic vehicles.

What Does It Do?

E10 Additive helps improve fuel combustion and acceleration, particularly under partial engine load.

It also cleans the fuel system and provides corrosion protection against moisture-related deterioration.

Why Is It Important?

E10 petrol contains up to 10% ethanol, which can affect fuel system materials and performance in certain vehicles.

The additive helps compensate for some combustion-related performance effects while providing additional protection against corrosion.

When Should It Be Used?

Use when filling a compatible Porsche petrol engine with E10 fuel or when additional fuel system protection is required.

It is particularly relevant for petrol-powered vehicles where smoother acceleration and protection against moisture-related corrosion are desired.

Application & Dosage

• Add directly to the petrol tank.
• One 150ml can treats 35–70 litres of petrol.
• The additive mixes automatically with the fuel.
• Suitable for use with different petrol grades.
• Follow the recommended dosage and the vehicle manufacturer's fuel requirements.

Key Features

• LIQUI MOLY E10 Additive
• 150ml container
• Developed for E10 petrol
• Helps improve combustion efficiency
• Supports smoother acceleration
• Improves drivability under partial load
• Cleans the fuel system
• Provides corrosion protection
• Protects against increased water content in fuel
• Ash-free formulation
• Contains no organometallic compounds
• Tested for use with catalytic converters

LIQUI MOLY E10 Petrol Additives for Porsche Engines

Modern petrol fuels can contain ethanol, making correct fuel selection and fuel system maintenance particularly important for Porsche owners.

LIQUI MOLY E10 Additive helps improve combustion, maintain smoother acceleration and protect fuel system components against corrosion.

It can be used in compatible petrol-powered Porsche engines, including 911, Boxster, Cayman, 944, 928, Cayenne, Macan and Panamera models.

For classic Porsche vehicles, always confirm that the engine and fuel system are approved for the petrol grade being used.

LIQUI MOLY Injection Cleaner – 300ml

LIQUI MOLY Injection Cleaner is a petrol fuel additive designed to remove deposits from fuel injectors, intake valves, spark plugs and combustion chambers.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche Boxster 987 2.7L 2005-08/08
• Porsche Boxster 987 S 3.2/3.4L 2005-08/08
• Porsche Boxster 987 MKII 2.9L 2009-12
• Porsche Boxster S 987 MKII 3.4L 2009-12
• Porsche Boxster 981 2.7L 2012-16
• Porsche Boxster 981 S / GTS 3.4L 2012-16
• Porsche Boxster 981 Spyder 3.8L 2016
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche 997 MK1 Carrera 2 3.6L 2005-08
• Porsche 997 MK1 Carrera 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche 997 MKII Carrera C2 3.6L 2009-12
• Porsche 997 MKII Carrera C4 3.6L 2009-12
• Porsche 997 MKII Carrera C2S 3.8L 2009-12
• Porsche 997 MKII Carrera C4S 3.8L 2009-12
• Porsche 997 MKII GT3 / GT3 RS 2010-11
• Porsche 997 MKII Turbo 2010-13
• Porsche 997 MKII GT2 RS 2011-13
• Porsche Cayman 2.7L 987C 2006-08
• Porsche Cayman S 3.4L 987C 2005-08
• Porsche Cayman 2.9L 987C MKII 2009-12
• Porsche Cayman S / R 3.4L 987C MKII 2009-12
• Porsche Cayman 2.7L 981 2013-16
• Porsche Cayman S / GTS 3.4L 981 2013-16
• Porsche Cayman GT4 3.8L 2015-16
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-95
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-91
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

It helps improve throttle response, reduce rough engine running and maintain efficient combustion. Suitable for compatible classic and modern Porsche petrol engines, including turbocharged models and vehicles fitted with catalytic converters.

LIQUI MOLY specifies suitability for all petrol engines, including turbocharged and catalytic-converter-equipped vehicles. These Porsche applications are indicative rather than individually approved.

Not suitable for diesel engines. In direct-injection engines, a fuel-tank additive does not directly clean the backs of intake valves.

What Does It Do?

Injection Cleaner removes deposits from petrol injection systems and fuel-contacted engine components.

It helps restore consistent fuel delivery, improve throttle response and reduce starting difficulties caused by contamination.

Why Is It Important?

Over time, fuel residues and combustion deposits can affect engine operation.

Common symptoms include:

• Rough or uneven idling
• Poor throttle response
• Difficult starting
• Reduced engine performance
• Deposits affecting injector operation

When Should It Be Used?

Use as a preventative fuel system treatment or when injector deposits are suspected of causing running problems.

Suitable for regular maintenance of petrol-powered Porsche vehicles, particularly older or infrequently driven models.

Application & Dosage

• Add directly to the petrol tank.
• One 300ml can treats up to 70 litres of petrol.
• The additive mixes automatically with the fuel.
• Provides a cleaning effect lasting up to 2,000km.
• Repeat treatment if symptoms return.

Key Features

• Product reference 1803 300ml container
• Cleans petrol injection systems
• Helps remove injector and combustion deposits
• Reduces starting difficulties and rough running
• Improves throttle response
• Supports efficient engine performance
• Helps prevent new deposits forming
• Tested for turbochargers and catalytic converters
• Suitable for petrol engines

LIQUI MOLY Fuel Injection Cleaners & Petrol Additives for Porsche

Keeping fuel injectors and combustion components clean helps maintain reliable engine performance, smooth running and efficient fuel delivery.

LIQUI MOLY Injection Cleaner helps remove deposits and prevent further build-up in compatible Porsche petrol engines, making it useful for both classic and modern models.

It is particularly relevant for Porsche 911, 944, 928, Boxster and Cayman owners seeking a straightforward fuel system maintenance treatment.

LIQUI MOLY Valve Cleaner – 150ml

LIQUI MOLY Valve Cleaner is a petrol fuel additive designed to remove deposits from engine valves and combustion chambers while helping prevent further build-up.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche Boxster 987 2.7L 2005-08/08
• Porsche Boxster 987 S 3.2/3.4L 2005-08/08
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche 997 MK1 Carrera 2 3.6L 2005-08
• Porsche 997 MK1 Carrera 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche Cayman 2.7L 987C 2006-08
• Porsche Cayman S 3.4L 987C 2005-08
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-88
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-91
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

It supports engine performance, improves compression where deposits are affecting valve sealing and provides corrosion protection. Ideal for compatible classic and modern Porsche petrol engines.

LIQUI MOLY specifies this product for petrol engines with carburettors or manifold fuel injection. The models listed are indicative applications, not individual Porsche approvals. Confirm the engine's fuel-injection system before use.

For direct-injection Porsche engines, a fuel-tank additive will not directly wash the backs of the intake valves.

What Does It Do?

Valve Cleaner removes deposits from valves and combustion chambers, helping restore efficient engine operation and maintain performance.

It also provides corrosion protection and helps prevent new deposits from forming.

Why Is It Important?

Carbon and combustion deposits can accumulate over time, particularly in older or infrequently driven petrol engines.

Excessive deposits may contribute to rough running, reduced engine performance and poor valve sealing.

When Should It Be Used?

Use as a preventative fuel system treatment or when deposits are suspected of affecting engine performance.

Particularly useful for classic Porsche engines with carburettors or manifold fuel injection.

Application & Dosage

• Add directly to the petrol tank when refuelling.
• One 150ml can treats up to 75 litres of petrol.
• Suitable for preventative maintenance or treatment of existing deposits.
• Follow the manufacturer's instructions and avoid exceeding the recommended dosage.

Key Features

• Product reference 2952
• 150ml container
• Removes deposits from valves and combustion chambers
• Helps prevent new deposits forming
• Supports engine performance and compression
• Provides corrosion protection
• Suitable for carburettor and manifold-injection petrol engines
• Tested for turbochargers and catalytic converters
• Simple fuel-tank application

LIQUI MOLY Valve Cleaning Additives for Porsche Petrol Engines

Clean engine valves and combustion chambers help maintain efficient combustion, reliable running and consistent engine performance.

LIQUI MOLY Valve Cleaner is particularly suited to classic Porsche 356, 911, 912, 914, 944 and 928 petrol engines using compatible carburettor or manifold fuel-injection systems.

Its cleaning formulation helps remove existing deposits while reducing further build-up.

LIQUI MOLY Carburetor and Valve Cleaner – 300ml 

LIQUI MOLY Carburetor and Valve Cleaner is a petrol fuel additive designed to remove deposits from carburettors, valves, spark plugs and combustion chambers.

Fits:

• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)

It helps restore engine performance, improve combustion and prevent new deposits from forming. Suitable for classic Porsche engines.

What Does It Do?

The additive cleans deposits from carburettors and engine components exposed to fuel and combustion.

It helps improve engine performance, maintain compression, reduce the risk of knocking combustion and prevent carburettor icing.

Why Is It Important?

Over time, fuel residues and combustion deposits can accumulate within the engine.

These deposits may contribute to:

• Rough or uneven engine operation
• Reduced engine performance
• Poor throttle response
• Increased risk of engine knocking
• Carburettor icing in suitable conditions

When Should It Be Used?

Use as a preventative fuel system treatment or when deposits are suspected of affecting engine operation.

Particularly useful for classic Porsche vehicles with carburettors and petrol engines requiring periodic fuel system maintenance.

Application & Dosage

• Add directly to the petrol tank.
• One 300ml can treats up to 70 litres of petrol.
• The additive mixes automatically with the fuel.
• Recommended treatment interval: every 2,000km.
• The fuel tank should be at least half full when adding.
• LIQUI MOLY also permits direct application to the carburettor, following the manufacturer's instructions.

Key Features

• 300ml container
• Cleans carburettors, valves and combustion chambers
• Helps remove deposits from spark plugs
• Prevents new deposits from forming
• Supports engine performance and compression
• Reduces the risk of knocking combustion
• Helps prevent carburettor icing
• Provides corrosion protection
• Tested for turbochargers and catalytic converters
• Suitable for petrol engines

LIQUI MOLY Carburettor & Valve Cleaning Additives for Porsche

Keeping the fuel system and combustion components clean helps maintain reliable performance in classic and modern Porsche petrol engines.

LIQUI MOLY Carburetor and Valve Cleaner removes deposits and helps prevent further build-up, making it particularly useful for carburettor-equipped Porsche 356, 911 and 912 models.

It can also be used in compatible fuel-injected Porsche petrol engines as part of regular maintenance.

LIQUI MOLY Pro-Line Oil Leak Stop – 1ltr

LIQUI MOLY Pro-Line Oil Leak Stop is a professional engine oil additive designed to help reduce oil leaks, excessive oil consumption and blue exhaust smoke caused by ageing engine seals.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-91
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

Its formulation helps restore flexibility to hardened or shrunken rubber and plastic seals, improving their sealing performance while supporting quieter engine operation.

Confirm compatibility with the vehicle's engine oil requirements before use. Not applicable to fully electric Porsche powertrains.

What Does It Do?

Pro-Line Oil Leak Stop helps regenerate rubber and plastic engine seals, including shaft seals and valve stem seals.

It can reduce oil consumption caused by deteriorated seals and help minimise blue exhaust smoke associated with oil entering the combustion chambers.

The additive also helps maintain oil viscosity and reduce engine noise.

Why Do Engine Oil Leaks Occur?

Common causes include:

• Hardened or shrunken engine seals
• Age-related rubber deterioration
• Heat and repeated temperature changes
• Porous or ageing sealing materials
• Worn or damaged engine components

When Should It Be Used?

Use when minor engine oil leaks or increased oil consumption may be caused by ageing rubber or plastic seals.

It is particularly useful for older Porsche engines where seals have hardened over time.

The additive cannot repair cracked housings, damaged gaskets or severely worn mechanical components.

Application & Dosage

• Add directly to the existing engine oil.
• One 1-litre container treats up to 15 litres of engine oil.
• Adjust the dosage proportionally for smaller oil capacities.
• Can be added at any time.
• After adding, warm the engine or drive the vehicle.
• The sealing effect typically begins after approximately 600–800km.
• LIQUI MOLY recommends repeating the treatment after each oil change for lasting results.

Key Features

• LIQUI MOLY Pro-Line professional additive
• 1-litre container
• Helps reduce leaks from ageing engine seals
• Restores flexibility to rubber and plastic seals
• Helps reduce engine oil consumption
• Can reduce blue exhaust smoke
• Supports quieter engine operation
• Suitable for petrol and diesel engines
• Compatible with engines fitted with diesel particulate filters
• Mixes with commercially available engine oils
• Not suitable for wet-clutch motorcycles

LIQUI MOLY Oil Leak Stop Additives for Porsche Engines

Ageing engine seals can become hard, brittle or shrunken, allowing oil to escape and increasing oil consumption.

LIQUI MOLY Pro-Line Oil Leak Stop helps restore the flexibility of suitable rubber and plastic seals, making it a useful maintenance treatment for compatible classic and modern Porsche engines.

It may be particularly beneficial for older Porsche 911, 964, 993, 944 and 928 models experiencing minor leaks caused by deteriorated seals.

LIQUI MOLY Petrol Stabilizer – 250ml 

LIQUI MOLY Petrol Stabilizer is a fuel additive designed to protect petrol against ageing and oxidation during vehicle storage. Ideal for classic, seasonal and infrequently driven Porsche vehicles, it helps prevent corrosion throughout the fuel system and supports reliable engine starting after extended periods of inactivity.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04
• Porsche Boxster 987 2.7L 2005-08/08
• Porsche Boxster 987 S 3.2/3.4L 2005-08/08
• Porsche Boxster 987 MKII 2.9L 2009-12
• Porsche Boxster S 987 MKII 3.4L 2009-12
• Porsche Boxster 981 2.7L 2012-16
• Porsche Boxster 981 S / GTS 3.4L 2012-16
• Porsche Boxster 981 Spyder 3.8L 2016
• Porsche 911 1965-1968 2.0L / 912 SWB (F)
• Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 911 1975-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93
• Porsche 964 (911) TURBO 3.3L 1991-93
• Porsche 964 (911) TURBO 3.6L 1991-93
• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) RS 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 996 GT3 RS 2003-04
• Porsche Cayman 2.7L 987C 2006-08
• Porsche Cayman S 3.4L 987C 2005-08
• Porsche Cayman 2.9L 987C MKII 2009-12
• Porsche Cayman S / R 3.4L 987C MKII 2009-12
• Porsche Cayman 2.7L 981 2013-16
• Porsche Cayman S / GTS 3.4L 981 2013-16
• Porsche Cayman GT4 3.8L 2015-16
• Porsche 924 2.0L 1976-79
• Porsche 924 2.0L 1980-85
• Porsche 924 Turbo 2.0L 1979-81
• Porsche 924 Turbo 2.0L 1982-84
• Porsche 924 Carrera GT 2.0L 1981
• Porsche 924 Carrera GTS 2.0L 1982
• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94
• Porsche 928 4.5L 1978-82
• Porsche 928S 4.7L 1981-83
• Porsche 928S2 4.7L 1984-86
• Porsche 928S4 5.0L 1987-92
• Porsche 928GT 5.0L 1989-91
• Porsche 928GTS 5.4L 1992-95
• Porsche 356 1950-55
• Porsche 356A 1955-59
• Porsche 356B 1959-63
• Porsche 356C 1963-65
• Porsche 914 (1970-1976)
• Porsche 912E 4CYL 1976

LIQUI MOLY states that the additive is suitable for all petrol engines and has been tested for use with turbochargers and catalytic converters.

The list represents general petrol-engine compatibility rather than individual Porsche approvals. It is not intended for diesel engines or fully electric vehicles.

What Does It Do?

Petrol Stabilizer helps preserve fuel quality by reducing oxidation and ageing during storage.

It also protects fuel system components against corrosion, helping maintain reliable operation when the vehicle is returned to use.

Why Is It Important?

Petrol can deteriorate when stored for extended periods, particularly in vehicles that are driven infrequently.

Fuel ageing and oxidation can contribute to deposits, corrosion and starting difficulties after storage.

When Should It Be Used?

Use before placing a Porsche into seasonal or long-term storage.

Particularly suitable for classic Porsche models, weekend cars and vehicles that remain unused for several months.

It can also be used regularly in infrequently driven petrol engines.

Application & Dosage

• Add directly to the petrol tank.
• Use 25ml for every 5 litres of petrol.
• One 250ml bottle treats up to 50 litres of petrol.
• Before storage, add the correct quantity and run the engine for approximately 10 minutes.
• Repeat the dosage after refuelling when continued protection is required.

Key Features

• LIQUI MOLY Petrol Stabilizer
• Product reference 21646
• 250ml dispensing bottle
• Protects petrol against ageing and oxidation
• Helps prevent fuel system corrosion
• Supports reliable starting after storage
• Long-lasting protective effect
• Suitable for all petrol engines
• Tested for turbochargers and catalytic converters
• Ideal for classic and infrequently driven Porsche vehicles

LIQUI MOLY Petrol Stabilizers & Porsche Fuel Storage Additives

Classic and modern Porsche petrol engines benefit from properly maintained fuel during extended periods of inactivity.

LIQUI MOLY Petrol Stabilizer helps preserve petrol quality, protect fuel system components and reduce storage-related problems.

Particularly useful for classic Porsche 356, 911, 912 and 914 models, as well as modern Porsche sports cars stored over winter.