Massachusetts
(Massachusetts General Law Chapter 90)
Summary:
Massachusetts has a general lift limit (2 inches) but allows taller lifts for 4x4s, determined by a mathematical formula.
Height (§7P):
"No person shall alter, modify or change the height of a motor vehicle with an original manufacturer's gross vehicle weight rating of up to and including 10,000 pounds, by elevating or lowering the chassis or body by more than 2 inches above or below the original manufacturer's specified height by use of so-called 'shackle lift kits' for leaf springs or by use of lift kits for coil springs, tires, or any other means or device." However, "The registrar shall establish rules and regulations for such changes in the height of motor vehicles beyond said 2 inches. No motor vehicle that has been so altered, modified or changed beyond the provisions of this section or the rules and regulations established by the registrar shall be operated on any way." Thus:
Alteration of Motor Vehicle Height (§540 CMR 6.00):
"The purpose of 540 CMR 6.00 is to provide rules and regulations for altering the height of four-wheel drive motor vehicles by elevating or lowering the chassis or body more than 2 inches above or below the original manufacturer's height ... 540 CMR 6.00 is adopted by the Registrar of Motor Vehicles ... to regulate alterations to the height of four-wheel drive vehicles with an original manufacturer's gross vehicle weight rating of not over 10,000 ..."
6.04: General Requirements:
"No motor vehicle shall be altered or modified in any way that may cause the vehicle body or chassis to come in contact with the roadway, expose the fuel tank to damage from collision, or cause the tires to come in contact with the body, chassis, or steering components under normal operation. The horizontal plane, front to rear, shall not differ more than 2 inches. ... The wheel track may be increased by the use of tires and rims for a maximum total increase of 4 inches beyond the original manufacturer's specification. The use of spacers to increase the wheel track is prohibited. Fractions shall be excluded in all measurements and final calculations.
6.05 Maximum Combined Mechanical and Tire Lift:
"(1) The maximum mechanical lift for four-wheel drive motor vehicles shall be calculated by multiplying the wheelbase times the wheel track, and dividing the product by a safety factor of 2,200: i.e., 92 inches w/b x 58 inches w/t = 5,336/2,200 = 2 inches (maximum mechanical lift). The outside diameter of the largest tire size available from the original manufacturer as standard or optional equipment for the particular motor vehicle may also be increased up to an amount equal to the maximum mechanical lift calculated. (2) The maximum combined mechanical and tire lift shall be no greater than the sum of the maximum mechanical lift and increased tire size calculated for the particular vehicle. (3) Reconstructed motor vehicles shall be limited to the maximum combined lift allowed for the particular chassis used, in accordance with the applicable provisions of 540 CMR 6.05 (1) and (2), i.e., a vehicle having a 65-inch track, a 105-inch wheelbase, and an original manufacturer's door height of 21 inches is allowed a maximum combined lift of 4 inches above the original manufacturer's door height. Accordingly, the lower edge of the door, door edge line, or floor panel, as stipulated in the general requirements of 540 CMR 6.00, of any unladen body mounted on such chassis may not exceed 25 inches above the level surface upon which the vehicle rests. (4) In doubtful cases, or in any case where the original manufacturer's specified height is not known or available, or where a motor vehicle is assembled without using a particular body and/or chassis (i.e., homemade), the Registrar shall determine the allowable maximum height and may issue a permit authorizing the operation thereof."
Source
General Laws of Massachusetts
www.mass.gov/legis/laws/mgl/gl-90-toc.htm