Subaru News (BLOG)

Welcome to Subaru News, Suburb Service’s monthly blog! Subaru News is meant to educate, entertain, and engage you in monthly musings on such topics as auto mechanics, Subarus, travel, auto repair, and driving and living in the Lake Forest Park and Shoreline area. Our blogs are released on the first day of each month!

What Kind of Gas Should I Put in My Subaru?

According to the Federal Trade Commission, using a higher octane gasoline than your manufacturer recommends does not offer any benefit. If your Subaru has standard specifications and does not carry a warning to use only premium gas, regular gasoline should not affect performance. However, if your Subaru engine is turbocharged, follow manufacturer recommendations and use only premium gasoline. The Forester, Outback, Impreza and Legacy offer a turbo option, for increased power and performance.

Turbo Engines and Octane Rating

What is a turbo engine?

According to Subaru Drive Magazine: The turbocharger, commonly called a "turbo," is operated by the energy contained in the exhaust gas. The exhaust gas spins a turbine inside the turbocharger at an extremely high speed (more than 100,000 rpm). That compresses the air/fuel mixture into the cylinders, which creates higher power output.

Turbo engines offer an increase in engine power with little increase in weight; however, they do require special care. Turbo engines are knock limited, meaning they will begin to knock before Minimum ignition advance for Best Torque (MBT) is reached, resulting in power loss and possible engine damage. Although modern turbo vehicles utilize the onboard computer to limit knock, reduce power, and prevent engine damage, the use of lower octane gas will still result in significant loss of power and fuel economy. Using low octane gas in an older model turbocharged engine without an onboard computer can cause significant engine damage in a short period of time.

Regular vs. Premium, is Premium Worth It?

If your Subaru is not equipped with a turbocharged engine and does not carry a warning to use only high-octane gas, regular gasoline should be sufficient. According to the FTC, "high octane gasoline does not outperform regular octane in preventing engine deposits from forming, in removing them, or in cleaning your car's engine." If you find that at any time your Subaru engine knocks or "pings," it may benefit from higher octane gasoline. However, if your Subaru is turbocharged and/or carries a fuel octane warning, always follow the advice in your owner's manual and use only premium-grade gasoline.

To make an informed decision regarding quality of fuel to use, we suggest you visit the following website "" This is an independent fuel rating site lists all major fuel brands and retailers from good to bad. Suburb Service recommends only major quality brands of fuel be used in your Subaru.