RV weight ratings explained: GVWR, GAWR, GCWR, UVW and OCCC
Overloading is the most common weight problem with motorhomes – often unintentionally, because the labels are misread. This article explains the key ratings, the definition of the unloaded vehicle weight and how a weigh-in at a CAT scale works.
The key ratings on the labels
| Rating | Meaning | Relevance |
|---|---|---|
| GVWR | Gross vehicle weight rating | must never be exceeded when loaded |
| GAWR front / rear | Gross axle weight rating per axle | often at the limit first (rear axle!) |
| GCWR | Gross combination weight rating (vehicle + trailer) | for towing |
| UVW | Unloaded vehicle weight as built | starting point for the payload |
| OCCC | Occupant and cargo carrying capacity | what's left for people and cargo |
| Hitch rating / tongue weight | Maximum trailer weight and hitch load | tongue weight counts as payload |
The GVWR and GAWRs are on the certification label on the driver's door frame (required by 49 CFR Part 567). Motorhomes additionally carry the RVIA weight label with UVW and OCCC, and a tire placard with the recommended tire pressures.
What the unloaded vehicle weight includes
Per the RVIA label, the UVW is the weight of the motorhome as built at the factory with full fuel, engine oil and coolant – but without occupants, cargo, fresh water, propane or dealer-installed accessories. European figures are different: the EU “mass in running order” includes 165 lb (75 kg) for the driver and often some fresh water and a propane bottle.
The OCCC is defined as GVWR − UVW − weight of full fresh water (including the water heater) − weight of full propane. Everything that goes into the RV afterwards – people, food, gear, add-ons like solar panels or a bike rack – must fit within this number. On many motorhomes it's surprisingly small.
Payload calculator – adds up occupants, water, propane, cargo and add-ons
Axle ratings: the underestimated limit
Even if the gross weight fits, the rear axle can be overloaded: rear storage bays, bike racks, water tanks behind the axle and long overhangs act as levers. On many Class C and Class A motorhomes the rear GAWR is the real bottleneck. At the same time the front axle is unloaded – bad for steering and traction.
Bike rack calculator – calculates the leverage on both axles
Tires and weight
Tires have their own load rating printed on the sidewall, and the tire placard gives the cold inflation pressure for the GAWR. An overloaded or underinflated tire is a major cause of RV blowouts – after weighing, set the pressure per the tire manufacturer's load/inflation table for the actual axle load.
Weighing correctly
- Load the RV ready for travel (people, water as on the road, propane, gear).
- Find a scale: CAT scales at truck stops, some moving companies, gravel pits and dumps; RV rallies often offer wheel-position weighing.
- First weigh the whole vehicle, then only the front axle, then only the rear axle (axles individually on the platform). Wheel-by-wheel weighing shows side-to-side imbalance.
- Compare the values with GVWR and GAWRs and adjust the load – heavy items forward and low.
Sources
- 49 CFR § 571.110 (FMVSS 110) – tire selection, rims and motorhome load information labels
- 49 CFR Part 567 – vehicle certification label (GVWR, GAWR)
- RVIA weight label definitions (UVW, OCCC) and manufacturer weight information
Published 09/19/2026.