What’s the Difference Between Premium and Unleaded Gasoline?
Do you know what type of fuel is right for your vehicle? Learn about octane ratings and the difference between premium and unleaded gasoline.
What Are Octane Ratings?
Knowing octane ratings is key to understanding the difference between premium and unleaded gasoline.
According to the Department of Energy (DOE), fuel contains oxygen. This oxygen helps keep gas from prematurely igniting in the engine (known as “knocking”). An octane grade or rating is based on how much oxygen is in the fuel.
What Is Unleaded Gasoline?
Unleaded gasoline is fuel with an octane rating of around 87. However, the DOE says there are three different octane ratings for fuel:
- Unleaded Fuel: 87
- Mid-grade Fuel: 88-90
- Premium Fuel: 91-94
At the gas station, yellow stickers on gas pumps are required by the Federal Trade Commission (FTC) to indicate octane levels and help ensure consumers have the information they need.
How Is Premium Fuel Different From Regular Unleaded?
Premium fuel has a higher octane level compared to regular unleaded or mid-grade fuel. According to the FTC, higher octane ratings make fuel more resistant to “knocking.”
Knocking is caused when fuel prematurely combusts in one or more cylinders in the engine, says the FTC. This can lead to an audible engine knocking or pinging sound when you start your car. Consumer Reports notes that knocking could result in damage to the car’s engine over time.
While some vehicles require premium fuel, the majority of cars take regular unleaded fuel, says Consumer Reports. Using plus- or premium-grade fuels typically doesn’t affect your engine’s performance or resistance to wear-and-tear.
Remember to check your vehicle’s owner manual or ask a dealership for help to find out what kind of fuel is recommended for your car.