Cal. Veh. Code § 24008.5

(a) No person shall operate any motor vehicle with a frame height or body floor height greater than specified in subdivisions (b) and (c).

(b) The maximum frame height is as follows:

Vehicle Type	Frame Height
(1) Passenger vehicles, except housecars	23 inches
(2) All other motor vehicles, including housecars, as follows:
Up to 4,500 pounds GVWR	27 inches
4,501 to 7,500 pounds GVWR	30 inches
7,501 to 10,000 pounds GVWR	31 inches

(c) The lowest portion of the body floor shall not be more than five inches above the top of the frame.
(d) The following definitions govern the construction of this section:
1. (1) “Frame” means the main longitudinal structural members of the chassis of the vehicle or, for vehicles with unitized body construction, the lowest main longitudinal structural members of the body of the vehicle.
2. (2) “Frame height” means the vertical distance between the ground and the lowest point on the frame, measured when the vehicle is unladen on a level surface at the lowest point on the frame midway between the front axle and the second axle on the vehicle.
3. (3) “GVWR” means the manufacturer’s gross vehicle weight rating, as defined in Section 390, whether or not the vehicle is modified by use of parts not originally installed by the manufacturer.