Sport and Tuner Categories have the same fuel rules. Fuel has to be federally approved for use on public highways (no racing fuels), and you can only use E85 or the like if your vehicle owner's manual says you can. (That means you can't tune/reflash an ECU a car to run E85.)

You can run propane or natural gas if the setup is safe, and the car only runs on those types of fuels.