Mixing different gasolines can harm your car's engine

Drivers often consider mixing different types of gasoline at the pump as a cost-saving measure, but experts warn against this practice due to potential long-term consequences for a vehicle's engine.

The octane rating of gasoline is a critical indicator of its resistance to compression within the engine. This property is vital for preventing premature ignition, which can occur if the fuel ignites before the spark plug fires. Vehicles have specific octane requirements, typically detailed in the owner's manual or on the fuel tank cap. Using a lower octane fuel than recommended can lead to premature ignition, while using a higher octane fuel in an engine designed for lower octane may not be harmful but offers no benefit.

While a single instance of mixing fuels might not immediately disrupt the combustion cycle, consistent practice can negatively impact engine performance and damage components such as valves, spark plugs, and pistons over time. The consequences can range from reduced efficiency to more severe mechanical failures. Furthermore, mistakenly fueling a gasoline engine with diesel can cause severe damage, potentially immobilizing the vehicle and requiring costly repairs, including draining the entire fuel system.