"Qualified motor vehicle" means a motor vehicle used, designed, or maintained for transportation of persons or property that (a) has two axles and a gross vehicle weight or registered gross vehicle weight exceeding 26,000 pounds or 11,797 kilograms, (b) has three or more axles regardless of weight, or (c) is used in combination, when the weight of that combination exceeds 26,000 pounds or 11,797 kilograms gross vehicle weight. "Qualified motor vehicle" does not include recreational vehicles.
Ca. Rev. and Tax. Code § 60112