Experts Warn: Premium Fuels May Do More Harm Than Good in Older Cars

Gas stations often market these pricier fuel options as safe and exceptionally advantageous, yet mechanics' perspectives vary. The ADAC organization's research indicates that using the highest-quality fuels might only reduce consumption by approximately 1-5 percent.

Adam Lehnort, an expert from the ProfiAuto Service network, notes, based on mechanics' experiences, that specially refined fuels could cause damage. The cleaning additives they contain can dislodge deposits of accumulated pollutants, which then make their way into the engine oil. While it might appear beneficial for the engine to operate "cleanly" with regular oil changes, these deposits can affect the piston's seal in the cylinder. This leads to decreased compression and, as a result, a reduction in engine power. Additionally, detergent additives in premium fuels can wash away pollutants, potentially harming fuel injectors.

Premium fuels include anti-knock additives designed to prevent pistons and valves from burning out and even engine head damage due to knock combustion. However, fuel with a higher octane number might impede the combustion process in engines without a knock sensor. To truly benefit from fuel with increased octane numbers, altering the ignition timing advance is necessary.

In conclusion, Lehnort suggests turning to chemical fuel additives, which can be employed occasionally, as a more cost-effective alternative to consistently using premium fuels.