Vehicle weight

Scope

In regards to vehicle weight alone:

Regulatory citations

• 49 CFR Part 382 — Controlled substances and alcohol use and testing
• 49 CFR Part 383 — Commercial driver’s license standards; requirements and penalties
• 49 CFR Parts 390-399

Key definitions

• Gross vehicle weight (GVW): Though not defined in the FMCSRs, a vehicle’s “gross vehicle weight” is commonly held to be the actual weight of the vehicle itself (curb weight) plus all cargo and passengers. The GVW is not a limit or specification; rather it is the actual weight that is obtained when the fully loaded vehicle is driven onto a scale at any given time.
• Gross combination weight (GCW): Also not defined in the FMCSRs, the “gross combination weight” is understood to be the weight of a loaded towing vehicle (GVW) plus the weight of the fully loaded trailer(s) (plus passengers, fuel, etc.). It is the actual weight obtained when the vehicle and trailer(s) are weighed together on a scale.
• Gross vehicle weight rating (GVWR): As defined in 383.5 and 390.5, the GVWR is the value specified by the manufacturer as the loaded weight of a single motor vehicle. In other words, this is the maximum allowable weight of the fully loaded vehicle (including passengers, cargo, fuel, accessories, etc.), as determined by the vehicle’s manufacturer. Loading a vehicle beyond its rated carrying capacity compromises safety, so the GVW must never exceed the GVWR.
• Gross combination weight rating (GCWR): The GCWR of a vehicle is defined in 383.5 and 390.5 as the greater of either:
  • The value specified by the manufacturer of the power unit, if such a value is displayed on the Federal Motor Vehicle Safety Standard (FMVSS) certification label required by the National Highway Traffic Safety Administration (see “Weight Plate” below); or
  • The sum of the GVWRs or the GVWs of the power unit and the towed unit(s), or any combination of those, that produces the highest value.
    
    Note that the GCWR of the power unit will not be used to define a commercial motor vehicle when the power unit is not towing another vehicle.

Summary of requirements

Registered weight. A vehicle’s weight rating should not be confused with its registered weight. To reduce registration fees, vehicles are often registered at a lower weight than they are rated to carry. A vehicle’s registered weight, however, does not generally affect whether it is subject to the FMCSRs. For example, a vehicle with a GVWR of 27,000 pounds would require a CDL even if it is registered at 24,000 pounds.

Weight plate. A vehicle’s GVWR and GCWR are normally found on a manufacturer’s plate attached to the door or glove box, or on the front of each trailer. If the plate and/or VIN number are missing, an enforcement officer may use the sum of the GVWRs or the GVWs of the power unit and the towed unit(s), or any combination of those, to arrive at the highest value.

Modified weight. Similarly, if a vehicle is structurally modified to carry a heavier load, an enforcement officer may use the higher actual gross weight of the vehicle instead of the GVWR to determine the applicability of the safety rules, based on the authority provided in 390.33.

Vehicle class. A vehicle’s GVWR is also used to determine its class, as follows: