The NASCAR Cup Series returns to Iowa Speedway this weekend for the Iowa Corn 350 Powered by Ethanol, bringing the sport back to one of its newest and most competitive short tracks. Here’s everything to know about the 2025 Cup Series race at Iowa before the green flag drops this weekend. Fuel strategy decided the raceThe 2025 Iowa Corn 350 Powered by Ethanol was held on Aug. 3, 2025, and featured 350 laps around the 0.875-mile oval. This year’s Iowa Corn 350 Powered by Ethanol once again brings a loaded field to Newton, with several drivers entering the weekend carrying momentum. Defending winner William Byron also returns to Iowa hoping to become the race’s first repeat Cup Series winner.