Indiana Code Title 6. Taxation § 6-6-2.5-1

Sec. 1. As used in this chapter, “alternative fuel” means a liquefied petroleum gas, not including a biodiesel fuel or biodiesel blend, used in an internal combustion engine or motor to propel any form of vehicle, machine, or mechanical contrivance. The term includes all forms of fuel commonly or commercially known or sold as butane, propane, hydrogen, hythane, electricity, or any other fuel used to propel a motor vehicle on a highway that is not subject to the tax imposed under section 28 of this chapter or the tax imposed under IC 6-6-1.1.