The Iowa Corn Promotion Board and the Iowa Corn Growers Association will return as the title sponsor for Iowa Speedway's Verizon IndyCar Series race in 2015. Iowa Corn has been the sponsor since the first IndyCar race at the speedway in 2007. IndyCar race cars are powered by a 85 percent ethanol blend. This year's Iowa Corn Indy 300 presented by DeKalb is July 12. The race will be 50 laps longer than previous years.