May 20th, 2026

You might already be sitting on one of the best fuel deals in California without knowing it. Millions of Californians drive flex fuel vehicles — cars and trucks built to run on E85 — and have no idea. Here’s how to check yours right now.

Look at the gas cap or fuel door

The easiest place to start is the inside of your fuel door. Most flex fuel vehicles have a yellow gas cap or a yellow ring around the fuel filler neck. Some have a sticker that reads “E85/Gasoline” or “Flex Fuel.”

Check the badge on the back of your vehicle

Walk around to the rear of your car. Many manufacturers — GM, Ford, Chrysler, and others — put a “FlexFuel” or “FFV” badge on the trunk or tailgate. If you see it, you’re good to go. Some stickers may be located on the window of a door. 

Use our compatibility guide

Still not sure? The Pearson Fuels app includes a vehicle compatibility checker that lets you look up your year, make, and model in seconds. It’s the fastest way to get a definitive answer without digging through your owner’s manual. Our website also has a FAQ section.

Why it’s worth checking

With regular gas above $6 in many parts of California and E85 available for under $3 a gallon, the price difference is impossible to ignore. If your vehicle is flex fuel capable, you could be saving hundreds — or thousands — of dollars a year without changing anything about how you drive. 

The switch takes as long as a normal fill-up. Download the Pearson Fuels app, find your nearest station, and see what you’ve been missing.