NHTSA Compliance

NHTSA Letters
NHTSA Alterer Letter
NHTSA Modifier Letter

Concerning relabeling door tags to reflect revised passenger capacity of NCV converted vehicles
By way of background, the National Highway Traffic Safety Administration (NHTSA) administers a statute requiring that motor vehicles manufactured for sale in the United States or imported into the United States be manufactured to reduce the likelihood of motor vehicle crashes and of deaths and injuries when crashes do occur. We refer to that statute as the Vehicle Safety Act. It is codified at 49 U.S.C. 30101, et seq.

One of the agency's functions under the Vehicle Safety Act is to issue and enforce Federal motor vehicle safety standards (FMVSSs). These standards specify safety performance requirements for motor vehicles and/or items of motor vehicle equipment. Manufacturers of motor vehicles must certify compliance with all applicable safety standards and permanently apply a label to each vehicle stating that the vehicle complies with all applicable FMVSSs and providing the vehicle gross vehicle weight rating (GVWR).

NHTSA's regulations impose certain requirements on those who alter in certain ways a vehicle that has been previously certified by a manufacturer but not yet sold in good faith for purposes other than resale. Alterers are considered to be manufacturers and are responsible for ensuring that the vehicle meets all applicable federal safety standards when delivered to the first retail customer. Alterers must determine whether those modifications could affect the vehicle manufacturer's certification of compliance and, if so, must apply a label adjacent to the original manufacturer's certification label stating that the vehicle, as altered. conforms with all applicable standards.

This requirement was intended to address circumstances in which the cargo carrying capacity has been reduced because of the modification. The term GVWR is defined in 49 CFR 571.3 as "the value specified by the manufacturer as the loaded weight of a single vehicle." The GVWR informs vehicle owners how heavily the vehicle may be safely loaded. It also affects the vehicle's loading and other test conditions for the performance tests to ascertain whether the vehicle complies with applicable safety standards. The only express regulatory limitation on the GVWR that manufacturers may assign to their vehicles is set forth in 49 CFR 567.4(g)(3), which provides that the assigned GVWR "shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity." "Unloaded vehicle weight" is defined in 49 CFR 571.3 as "the weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo, occupants, or accessories that are ordinarily removed from the vehicle when they are not in use." Although the term "rated cargo load" is not defined by regulation, generally it is the GVWR of the vehicle minus the combined weight of the occupied designated seating positions (150 pounds times the total number of designated seating positions) and the unloaded vehicle weight.

Alterers must also determine whether their modifications affect the manufacturer's stated GVWR, gross axle weight rating (GAWR), and vehicle type. If such a change has been made, the Alterers must specify the new GVWR, GAWR, or vehicle type in a manner consistent with the capability of the vehicle to comply with applicable standards and operate at higher weight rating and/or as a different type of vehicle. NHTSA expects both manufacturers and alterers to assign GVWR and GAWRs that reflect the manufacturer's or alterer's good-faith evaluation of how the vehicle's braking, load bearing items (including tires), suspension, steering, and drive train components will react to the vehicle's weight, size, cargo-carrying capacity and intended use.

Although the term "load carrying capacity" was not specifically defined in the February 2001 final rule, the term was intended to convey the same meaning as vehicle capacity weight, as defined in FMVSS No. 110, Tire selection and rims. "Vehicle capacity weight" is defined in that standard as the rated cargo and luggage load plus 68 kilograms (150 pounds) times the vehicle's designated seating capacity. Simply stated, a vehicle's load carrying capacity is its GVWR minus its unloaded weight. Likewise, the term "available load capacity" means that load carrying capacity that remains after the modifications are completed.

The number of designated seating positions used to determine the load carrying capacity may not be the same as the number of designated seating positions that were in the vehicle when the vehicle manufacturer or alterer assigned the GVWR.


Jacqueline Glassman
Chief Counsel (NHTSA)