Donate |

Paying for premium gas can be a waste of money

Last updated: April 2014

 

Many people use premium gasoline thinking that it's better for their engine than regular. That can be a costly mistake, especially when gas prices are high. Octane grades don't represent a "good, better, best" choice; they simply measure the resistance of fuel to knocking or pinging, a condition in which gasoline burns uncontrollably in the engine's combustion chambers. Knocking and pinging can damage an engine.

While high-octane formulations resist knocking better than lower octanes, most engines are designed to take regular gas, which has an octane rating of about 87. Engines requiring premium gas are typically the more powerful ones found in sports and luxury vehicles, which are more vulnerable to knocking, so recommended fuels have octane ratings of 91 or higher. Using premium gas in an engine designed to run on regular doesn't improve performance.

Some engines for which premium gasoline is recommended can run on regular without problems. That's because the engine's knock-sensor system detects the presence of uncontrolled burning in the chambers. When it does, the engine's computer-control system retards engine timing, eliminating the knock but slightly reducing power. If you don't mind giving up some performance, you can run these engines on less-expensive regular gasoline. To check whether your engine is capable of running on regular gas, read your owner's manual or ask your dealership's service department.

 

   

E-mail Newsletters

FREE e-mail Newsletters!
Choose from cars, safety, health, and more!
Already signed-up?
Manage your newsletters here too.

Cars News

Connect

and safety with
subscribers and fans

Follow us on:

Cars

Cars New Car Price Report
Find out what the dealers don't want you to know! Get dealer pricing information on a new car with the New Car Price Report.

Order Your Report

Mobile

Mobile Get Ratings on the go and compare
while you shop

Learn more