Engine decarbonisation
petrol engines
Why it matters
Cleanliness of the internal engine components and their perfect lubrication are key to correct and trouble-free engine operation.
Engine technologies used today produce higher temperatures in the combustion chamber, work with higher pressures, with less sealing from the piston rings and with tighter tolerances. These conditions, together with extended oil change intervals, contribute to thickening of the engine oil and, over time, to sludge forming in the engine. Deposits on the piston rings prevent them from doing their job, which is to maintain correct compression pressures. The result is loss of engine power, increased fuel consumption, higher emissions and increased engine oil consumption.
To restore engine power and the condition of the internal components, the deposits formed on the piston rings must be removed. This restores cylinder compression and, with it, engine power. The next step is to prevent sludge from forming again. The final step is cleaning the fuel system. Three-stage deep cleaning of the engine with BG products forms the basis of the engine performance restoration service — the most cost-effective way to care for your engine in the long term.
Preventive vehicle maintenance
Treat your vehicle to BG products regularly and avoid unnecessary, costly repairs later on.
Request an appointmentWhen to act
Based on our experience, we recommend decarbonisation in cases where:
Extending the prescribed engine oil change interval degrades its lubricating ability. Engine components are subjected to greater stress and the risk of carbon build-up on components such as the piston rings increases. Hard deposits on the piston rings can mechanically damage the cylinder bore. The subsequent repair is expensive.
Engine oil consumption between prescribed changes can be caused by carbonised piston rings. They can no longer seal properly, so engine oil leaks into the cylinder and is burned. Increased engine oil consumption is an indicator for engine compartment decarbonisation.
A rising engine oil level between prescribed changes can be caused by fuel leaking into the engine oil, which indicates a problem with the condition of the piston rings. Since fuel does not lubricate like oil, engine components wear faster and the engine may eventually fail.
Products used
BG EPR® Engine Performance Restoration
BG EPR delivers highly effective decarbonisation of the oil compartment and the piston rings. It dissolves stubborn deposits from the piston rings and cleans micro-passages so that critical hydraulic components such as variable valve timing actuators and the turbocharger keep working. It restores the correct sealing function of the piston rings, compression pressures and engine power, and reduces emissions and engine oil consumption. The new oil enters a clean system with no risk of contamination or degradation.
BG MOA® Motor Oil Additive
BG MOA is a multi-spectrum additive for the engine oil of petrol engines. It prevents oxidation and degradation of the oil and thus extends its life. It prevents piston rings from sticking and reduces exhaust emissions. It minimises fouling of the intake and combustion system. Cleaning additives keep the engine and piston rings free of deposits and prevent sludge from forming. A high alkaline reserve protects engine parts against corrosion. It contains no substances incompatible with engine oils.
BG 44K® Fuel System Cleaner
BG 44K is designed for effective and safe removal of carbon deposits from the combustion and injection system of petrol engines. It is added to the fuel and offers maximum protection for direct injection engines (GDi, TSi, FSi and similar). It is safe for engines with a particulate filter. It cleans the entire fuel system including injectors, valves, lambda sensor, fuel filter and combustion chamber. It restores injection system performance, reduces fuel consumption, supports smooth running and reduces vibration.
How it works
The BG engine performance restoration service keeps your engine in perfect condition for as long as possible.
BG 44K is added to a full fuel tank.
BG EPR is added to the used, warmed-up oil in the quantity prescribed for the engine oil volume.
The engine runs at 1,200 rpm for 10 minutes, or 20 minutes for direct injection petrol engines. The deposits accumulated in the engine are dissolved by BG EPR and held in the used engine oil.
The used engine oil is drained together with the dissolved deposits.
The oil filter is replaced.
New Ravenol engine oil of the prescribed viscosity and quantity is filled in, together with the BG MOA engine oil conditioner for petrol engines.
The service interval in the vehicle on-board computer is reset.
The service is recorded in the electronic service book (VW Group, Mercedes, BMW, Ford).
Pricing
Pricing valid from 1 November 2025
| Service option | What's included | Price |
|---|---|---|
| Engine oil volume 3 – 4 litres |
BG decarbonisation of the oil, combustion and fuel system of a petrol engine. The price includes all work related to the BG decarbonisation and to the engine oil and filter change, as well as BG material in the prescribed quantity. Engine oil and oil filter are not included in the price. We recommend a fully synthetic Ravenol engine oil with the viscosity class specified by the vehicle manufacturer.
|
93 €incl. VAT |
| Engine oil volume 4 – 6 litres |
BG decarbonisation of the oil, combustion and fuel system of a petrol engine. The price includes all work related to the BG decarbonisation and to the engine oil and filter change, as well as BG material in the prescribed quantity. Engine oil and oil filter are not included in the price. We recommend a fully synthetic Ravenol engine oil with the viscosity class specified by the vehicle manufacturer.
|
113 €incl. VAT |
| Engine oil volume 6 – 9 litres |
BG decarbonisation of the oil, combustion and fuel system of a petrol engine. The price includes all work related to the BG decarbonisation and to the engine oil and filter change, as well as BG material in the prescribed quantity. Engine oil and oil filter are not included in the price. We recommend a fully synthetic Ravenol engine oil with the viscosity class specified by the vehicle manufacturer.
|
154 €incl. VAT |
| Engine oil volume 9 – 15 litres |
BG decarbonisation of the oil, combustion and fuel system of a petrol engine. The price includes all work related to the BG decarbonisation and to the engine oil and filter change, as well as BG material in the prescribed quantity. Engine oil and oil filter are not included in the price. We recommend a fully synthetic Ravenol engine oil with the viscosity class specified by the vehicle manufacturer.
|
231 €incl. VAT |
Request an appointment No obligation — we'll get back to you with the earliest available slot for your vehicle.
Piston rings before and after the service.
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