With gas prices constantly in flux, you may be using different octanes from one day to the next. However, this isn’t the best option for the health of your car. There really is a difference between fuel types – but the more expensive option isn’t always better.
What the Rating Really Is
Fuel is generally available in different grades or octane levels: 87 (regular), 88-89 (premium), and 91-94 octane (super premium). The octane rating is really nothing more than a measurement of how evenly the gasoline will burn when you accelerate hard.
Ideally, you want to achieve a smooth transfer of energy from the vaporized gasoline to the crankshaft and wheels. As the pressure increases, some gasoline vapors can form into small pockets and explode prematurely, and that leads to a knocking sound that you want to avoid.
All About the Car
High-performance vehicles are more likely to reach those demanding situations where the air pockets might form, so they need a higher-octane gas that won’t self-ignite quite as easily. With more consistent burning levels, the 91 octane fuel can help your sports car run smoothly. However, a family car won’t need the higher-octane fuel because it’s less likely to accelerate quickly or maintain very high speeds. In this case, you can safely drop down to the lower octane to save money when filling up.
Before you buy a car, ask about the fuel that it takes. If a manufacturer recommends or demands a certain level, then you’ll want to follow that advice throughout the life of the car. You’ll get the right performance and avoid problems down the road.