30 ILCS 532/5
As used in this Act:
"Agency" means the Environmental Protection Agency.
"Governmental unit" means the State or State agency.
"Law enforcement vehicle" means a publicly owned or leased vehicle that is operated by a law enforcement agency and used for the law enforcement functions of the agency.
"Passenger vehicle" means a motor vehicle, except a motorcycle, designed primarily for the transportation of persons and designed for carrying no more than 10 passengers, including the driver, and primarily used for the transportation of persons. "Passenger vehicle" includes motor vehicles which are designed with seats that may be readily removed and reinstalled, but does not include such vehicles if used primarily for the transportation of property. "Passenger vehicle" does not include vehicles purchased by the Department of Transportation as part of their consolidated vehicle procurement program.
"Zero-emission vehicle" means a passenger vehicle that produces zero exhaust emissions of any criteria pollutant, precursor pollutant, or greenhouse gas, but only produces water vapor, in any mode of operation or condition, as determined by the Agency.
30 ILCS 532/5