Any single vehicle, except a Class D motor vehicle, with a gross vehicle weight rating of twenty-six thousand one (26,001) or more pounds, or any such vehicle towing a vehicle not in excess of ten thousand (10,000) pounds gross vehicle weight rating. This class shall apply to a bus with a gross vehicle weight rating of twenty-six thousand one (26,001) or more pounds and designed to transport sixteen or more persons, including the driver.
Okla. Stat. tit. 47, § 1-107.2