The Effect of Higher Octane Ratings on Gas Mileage

Using a higher-octane gasoline than recommended in your owner's manual won't improve your gas mileage or engine performance, according to the Federal Trade Commission. Most cars are designed to use regular-octane gasoline.

Octane Levels

Octane levels refer to how well a gasoline resists engine knock, caused by premature ignition in a cylinder. Engine knock is characterized by a rattling or pinging sound. If your car has engine knock, switch to a higher-octane gasoline.

Significance

Higher-octane gasoline typically costs 15 to 20 cents more per gallon than regular gasoline. Choosing higher-octane gasoline instead of regular gasoline could cost hundreds of dollars a year.

Improving Gas Mileage

Improve your gas mileage by driving at the speed limit, reducing aggressive acceleration and quick stops and removing excess weight from your car. In addition, keep your engine tuned, inflate your tires properly and check air filters regularly.

References

• Federal Trade Commission: The Low-Down on High Octane Gasoline
• Federal Trade Commission: Good, Better, Best---How to Improve Gas Mileage