What is the Difference Between the Different Octane Fuels?

The octane rating of a fuel is a measure of its ability to resist “knocking” or “pinging” during combustion, caused by the air-fuel mixture detonating prematurely in the engine. The higher the octane rating, the more resistant the fuel is to knocking.

There are typically three octane ratings available for gasoline at most fuel stations:

1. Regular gasoline (85-87 octane): This is the most common gasoline sold and recommended for most cars that don’t require higher-octane fuel. It’s also the mot cost effective.
2. Mid-grade gasoline (89 octane): This gasoline has a higher octane rating than regular gasoline, which can improve engine performance in some vehicles.
3. Premium gasoline (91-93 octane): This gasoline has the highest octane rating and is recommended for high-performance or luxury cars that require it. It’s also the most expensive.

Using higher-octane gasoline than your car requires doesn’t provide any additional benefit to your engine or fuel efficiency. However, using lower-octane gasoline than recommended can cause engine knocking, decrease fuel efficiency, and potentially damage the engine over time.

Elevation can affect your octane needs. At higher elevations, the air is less dense, and there is less oxygen available for combustion in the engine. This can cause the engine to run leaner, meaning that there is a higher air-to-fuel ratio, which can lead to engine knocking or pinging.

In these situations, a higher octane fuel may be required to prevent engine knocking. However, the majority of modern cars are equipped with knock sensors that can detect engine knocking and adjust the engine timing to prevent it from happening, regardless of the altitude.

In short, unless you have a high-performance car that requires higher octane gasoline, or you notice engine knocking at high altitudes, always use the type of gasoline recommended by your vehicle’s manufacturer.