What Kind Of Fuel Does NASCAR Use In Its Race Cars?

The National Association for Stock Car Racing — NASCAR — has been a staple of the American motor racing scene since it held its first race at Daytona Beach on February 15, 1948, just a few months after the organization was founded. Today, only the NFL has more fans than NASCAR.

Races are held at 42 tracks across the U.S. and Canada, with NASCAR's Cup Series schedule for 2025 including 38 races. That opened on February 2, 2025, with its non-points Clash exhibition at Bowman Gray Stadium in Winston-Salem, NC.

With the average NASCAR vehicle capable of speeds up to 150-200 miles per hour, a high-performance fuel with low emissions helps keep these cars in optimal racing condition. So what powers NASCAR's fleet? Sunoco has been the official fuel of Nascar for over 20 seasons — that's over 18 million competitive miles. Initially, a high-octane leaded fuel was used across the board, but in 2008, the American auto racing company switched to Sunoco 260 GTX, an unleaded fuel.

Today, NASCAR uses Sunoco Green E15 in all its cars. The 98-octane unleaded fuel blend is specifically designed for race cars and high-performance vehicles, containing 15% American-made corn-based ethanol, which burns cleaner than conventional gasoline. It also contains additives designed to keep fuel systems clean by reducing deposits, and gets its name from the fact that the fuel is actually green.

Sunoco Green E15 was formulated following a partnership between Sunoco and American Ethanol in 2008 in a bid to reduce emissions. NASCAR switched to the new fuel type following in 2011, when it was first used at the Daytona International Speedway. In a 2013 discussion with Kurt Wagner of Fortune, NASCAR's Managing Director of Green Innovation, Mike Lynch, explained that the decision to move to the 15% blend hinged on the fact that it provides additional horsepower. The blend is also at a level where no changes need to be made to the car or the engine either, making the swap relatively smooth.

Fuel high in ethanol isn't just for race cars. According to the Environmental Protection Agency (EPA), E15 can be safely used in any gasoline-powered vehicle produced after 2001. Because it contains more ethanol than other fuel types, it can't be used safely in older vehicles, as it may corrode older components — particularly those made of rubber such as gaskets and fuel lines. It's therefore recommended that gasoline-powered vehicles produced before 2001 stick to E10 fuel.