Interpretation ID: aiam3037
President
Macdonald Equipment Company
P.O. Box B
7333 Highway 85
Commerce City
CO 80022;
Dear Mr. Dahm: This responds to your January 2, 1979, letter asking whether it i permissible to mount a snow plow on a vehicle when the weight of the snow plow will cause the vehicle to exceed its gross axle weight rating (GAWR). The answer to your question is no.; The GAWR of a vehicle is determined and established by a vehicle' manufacturer and represents a manufacturer's assessment of the maximum weight that each axle can safely sustain. When this weight rating is exceeded by the addition of equipment to a vehicle, the safety of a vehicle is jeopardized. Over a period of time, the excessive weight borne by the axle could result in unusual wear and eventual failure of the axle.; The National Highway Traffic Safety Administration require manufacturers to label their vehicles with GAWR's to avoid the overload problem that you mention in your letter. The NHTSA has not granted exceptions from this requirement for snow plows. If you mount a snow plow on a new vehicle prior to first purchase, you must be sure that the vehicle continues to comply with all Federal safety standards and regulations. If the weight of the plow exceeds the GAWR of the vehicle, the vehicle would no longer comply with Standard No. 120, *Tire Selection and Rims for Motor Vehicles Other Than Passenger Cars*. Further, the compliance of other safety standards could be impacted by the addition of that weight.; In the case of used vehicles on which you mount a snow plow, manufacturer, repair business, distributor, or dealer may not knowingly render inoperative the compliance of a vehicle with the safety standards. The attachment of a snow plow that exceeds the gross axle weight rating would render inoperative the compliance of the vehicle with Standard No. 120. Accordingly, whether a vehicle is new or used, the additional weight of a snow plow that would exceed the GAWR of a vehicle would not be permissible.; The NHTSA understands the budgetary constraints of municipalities However, financial considerations must be balanced against the potential loss of life that can occur when vehicles are routinely overloaded. Accordingly, vehicles that have snow plows or other devices mounted on them should have sufficient GAWR's to carry their intended load.; Sincerely, Frank Berndt, Chief Counsel