No person shall drive on a public highway any motor vehicle registered as a passenger motor vehicle if it has been modified by alteration of its altitude from the ground to the extent that its bumpers, measured to any point on the lower edge of the main horizontal bumper bar, exclusive of any bumper guards, are not within the range of fourteen inches to twenty-two inches above the ground. No vehicle shall be modified to cause the vehicle body or chassis to come in contact with the ground, expose the fuel tank to damage from collision, or cause the wheels to come in contact with the body under normal operation. No part of the original suspension system of a motor vehicle shall be disconnected to defeat the safe operation of its suspension system. However, nothing contained in this section shall prevent the installation of heavy duty equipment, including shock absorbers and overload springs. Nothing contained in this section shall prohibit the driving on a public highway of a motor vehicle with normal wear to the suspension system if such normal wear does not adversely affect the control of the vehicle. No person shall drive on a public highway any motor vehicle registered as a truck if it has been modified by alteration of its altitude from the ground to the extent that its bumpers, measured to any point on the lower edge of the main horizontal bumper bar, exclusive of any bumper guards, do not fall within the limits specified herein for its gross vehicle weight rating category. The front bumper height of trucks whose gross vehicle weight ratings are 4,500 pounds or less shall be no less than 14 inches and no more than 28 inches, and their rear bumper height shall be no less than 14 inches and no more than 28 inches. The front bumper height of trucks whose gross vehicle weight ratings are 4,501 pounds to 7,500 pounds shall be no less than 14 inches and no more than 29 inches, and their rear bumper height shall be no less than 14 inches and no more than 30 inches. The front bumper height of trucks whose gross vehicle weight ratings are 7,501 pounds to 15,000 pounds shall be no less than 14 inches and no more than 30 inches, and their rear bumper height shall be no less than 14 inches and no more than 31 inches. Bumper height limitations contained in this paragraph shall not apply to trucks with gross vehicle weight ratings in excess of 15,000 pounds. For the purpose of this section, “truck” includes pickup and panel trucks, and “gross vehicle weight ratings” means manufacturer’s gross vehicle weight ratings established for that vehicle as indicated by a number, plate, sticker, decal, or other device affixed to the vehicle by its manufacturer. In the absence of bumpers, and in cases where bumper heights have been lowered, height measurements under the foregoing provisions of this section shall be made to the bottom of the frame rail. However, if bumper heights have been raised, height measurements under the foregoing provisions of this section shall be made to the bottom of the main horizontal bumper bar. No vehicle shall be operated on a public highway if it has been modified by any means so as to raise its body more than three inches, in addition to any manufacturer’s spacers and bushings, above the vehicle’s frame rail or manufacturer’s attachment points on the frame rail. No passenger car or pickup or panel truck shall be operated on a public highway if the suspension, frame, or chassis has been modified by any means so as to cause the height of the front bumper to be four or more inches greater than the height of the rear bumper. This section shall not apply to specially designed or modified motor vehicles when driven off the public highways in races and similar events. Such motor vehicles may be lawfully towed on the highways of the Commonwealth.