Fuel Additives For Petrol And Diesel Engines

In theory, the use of fuel additives is not necessary for most engines. However, this only applies if the engine operates under ideal conditions, meaning it always has access to clean, high-quality fuel (not a problem in Germany) and the tank is at least half full most of the time. In practice, it is worthwhile to think about engine protection in advance, as in many cases, fuel additives – gasoline or diesel – are used preventively to protect the components of the fuel system from premature wear and failure.

It may surprise some drivers that even the best fuel can lead to contamination. Over time, deposits and other impurities, which are natural by-products of oil or fuel combustion, can accumulate in the combustion chamber or on engine components. We have summarized in our guide the problems that arise over time and how fuel additives can help prevent them.

Carbon Build-up on Gasoline Injectors

carbon-buildup-insidde-the-intake-manifold

Even with good fuel quality, deposits eventually form on the injectors or injectors. If these are not removed in time, they can lead to a defect of the injectors and necessitate the replacement of these expensive parts.

Especially in modern engines with gasoline direct injection, carbon deposits quickly form, both through the recirculated exhaust gases from the crankcase ventilation as well as from the EGR valve on the intake valves. Engines with intake manifold injection are also affected, but the intake valves are cleaned again by the flowing fuel.

Injector additives (so-called 'injector cleaners') balance out the negative effects of the accumulation of various types of impurities in the injection system and protect the system from corrosion. They are used from time to time as a preventive measure and not at every refueling.

Carbon Build-up on Diesel Injectors

Those who drive a diesel should consider the use of diesel additives. These serve to remove impurities, have a preservative effect, and also optimize engine performance, clean the injectors, and thus prevent premature wear.

Diesel additives are very effective and can therefore dissolve various deposits and carbon build-up. They are excellent for situations with a heavily contaminated fuel system and for preventive maintenance.

Clogged Diesel Particulate Filters

diesel-particulate-filter-cleaner

The diesel particulate filter (DPF) is a great invention that benefits our health and the environment. In principle, it should not cause any problems if the car is used properly on long journeys. However, those who mainly drive short distances give the DPF almost no opportunity to get up to speed and burn off.

Fuel additives help eliminate soot, but do not remove ash from the filter. This can only be done by a professional workshop. With the right additives, at least an expensive workshop visit can be prevented, or at least the cleaning of the DPF in a workshop can be made somewhat easier through the regular use of such additives.

For years, car manufacturers have prohibited the use of such additives in the operating instructions, but now such radical restrictions are no longer imposed. In addition, the exhaust gas aftertreatment was simply implemented incorrectly in some diesel models by placing the particulate filter too far from the engine, which meant that the operating temperature was never reached for a long time and the soot therefore took significantly longer to burn off. As a reminder: to remove the soot from the particulate filter, it must be heated to 500 to 600 degrees Celsius (932 to 1112 degrees Fahrenheit).

Water in the Tank

Not everyone who stops at the gas station fills up the tank. Some drivers try to drive almost to the last drop and just refuel enough so that the fuel gauge rises slightly above the reserve. The crux of the matter, however, is that moisture accumulates on the walls of an almost empty tank.

If a lot of water accumulates, it flows into the tank and dilutes and contaminates the fuel mixture. All of this together can have unsightly consequences for the entire drivetrain. To avoid expensive repairs, preparations should be used that prevent the accumulation of water and protect the tank from corrosion.

Are Fuel Additives Harmful to the Engine?

Fuel additives can be used for all engines, including new ones. Of course, it is important to check before use whether the product is really suitable for the engine. However, their use is most sensible for engines that are 10 years or older, and/or if the car is mainly driven on short distances in city traffic.

Does the Manufacturer's Warranty Expire When Applied?

Then there are the car manufacturers themselves, who have a say in the matter. The operating instructions often point out that the use of additives leads to the expiration of the manufacturer's warranty. If an engine damage occurs and it is subsequently found that an additive was mixed with the fuel beforehand, a less accommodating manufacturer could refuse to take over the repair costs.

The reasons for this are usually quite vague and contradict (how could it be otherwise) the opposite view of the manufacturers of fuel additives. However, this mainly concerns new car buyers and buyers of young used cars – for those interested in older vehicles, which are no longer covered by the manufacturer's warranty, this is rather uninteresting.

Conclusion

The use of additives eliminates harmful compounds, cleans the engine of deposits, prevents corrosion, and improves the combustion of the fuel-air mixture. As a result, the engine not only runs better and longer, but also consumes less fuel. However, it should not be forgotten that fuel additives only have a preventive effect and cannot reverse existing damage.