July 7th, 2026

E85 has been available for decades, yet many drivers still aren’t sure what it is or how it differs from gasoline.

E85 is a high-octane fuel blend made primarily from ethanol and designed for flex fuel vehicles. Here’s how it compares to gasoline and why more California drivers are making the switch.

What each fuel is made of

Gasoline is a refined petroleum product made from crude oil. The 87, 89, and 91 grades found at a standard California pump refer to octane rating.

E85 is a blend of approximately 85 percent ethanol and 15 percent gasoline. The ethanol is produced domestically, primarily from corn. Because ethanol and gasoline have different properties, they perform differently inside an engine.

Octane

One of the biggest differences between E85 and gasoline is octane.

Regular gasoline is rated at 87 octane. California premium is rated at 91 octane. E85 at Pearson Fuels stations is rated at 100 octane or higher.

Octane measures a fuel’s resistance to engine knock. E85’s higher octane rating is one reason it has become popular among performance enthusiasts and drivers looking to get more from compatible vehicles.

For most stock vehicles, the difference may not be noticeable. Vehicles designed or tuned to take advantage of higher-octane fuel, however, can see meaningful performance benefits.

Combustion temperature

E85 provides greater charge cooling than gasoline because ethanol absorbs heat as it evaporates.

As ethanol evaporates, it naturally absorbs heat, which can help reduce engine temperatures under demanding conditions. That’s one reason E85 has long been used in performance applications.

Fuel economy

Because E85 contains less energy per gallon than gasoline, vehicles running E85 typically experience lower fuel economy.

However, fuel economy is only part of the equation. E85 is consistently priced significantly lower than regular gasoline in California, with the price gap sometimes exceeding $2.00 per gallon. For many drivers, that lower price more than offsets the reduction in fuel economy.

Emissions

E85 can help reduce lifecycle greenhouse gas emissions compared to conventional gasoline. Because ethanol is produced from renewable feedstocks, its lifecycle emissions profile differs from petroleum-based fuels.

That’s one reason E85 plays a role in California’s broader clean fuel strategy.

Compatibility

Any vehicle labeled as a flex fuel vehicle (FFV) can operate on E85, gasoline, or any blend of the two. Approximately 1.1 million flex fuel vehicles are already on California roads.

Flex fuel vehicles automatically detect the fuel blend and adjust engine operation accordingly. No modifications are required.

AB 2046, the Access to Affordable Gas Act, is currently before the California Senate after passing the Assembly. If enacted, it would allow owners of compatible vehicles to legally install EPA-approved conversion technology and operate on E85.

For California flex fuel vehicle owners, E85 offers a combination of higher octane, lower fuel costs, and reduced lifecycle emissions. As California’s E85 network continues to grow, it’s becoming an increasingly practical alternative to gasoline for compatible vehicles.