HB 4399

Amends the Illinois Vehicle Code. Provides that, beginning July 1, 2027, a diesel powered vehicle owned or operated by the State, any county or unit of local government, any school district, any community college or public college or university, or any mass transit agency must use a biodiesel blend that contains 19%, unless the engine is designed or retrofitted to operate on a higher percentage of biodiesel or on ultra low sulfur fuel. Allows, in December, January, February, and March, a biodiesel blend of at least 10% to be used. Effective immediately.