Recreational vehicle manufacturer Fleetwood Enterprises Inc. has published on its Web site, www.fleetwoodrv.com, data on RV tire care-including proper inflation pressures-a safety guide and information about proper vehicle weights.
The company said the major components of an RV-the vehicle frame, brakes, axles, rims, tires etc.-are designed to accommodate a particular weight. If these weight ratings are exceeded, these parts may wear rapidly. RV manufacturers provide weight ratings and load specifications printed on the vehicle certification label. The following are five weight-related terms RV owners and anyone servicing an RV should know:
Gross Vehicle Weight Rating (GVWR):
GVWR is the weight rating established by the chassis manufacturer as the maximum weight (including vehicle, cargo, liquids, passengers etc.) that the components of the chassis are designed to support.
Gross Axle Weight Rating (GAWR) for each axle:
This is the maximum weight rating that components of each axle are designed to support (that is, tires, wheels, brakes, springs, axle). This is determined by the lowest design capacity of any component. In other words, if the wheels have the lowest design capacity of any component on that axle, installing tires with a higher load capacity does not increase the GAWR.
Gross Combined Weight Rating (GCWR):
This represents the maximum allowable total loaded weight rating of the motor vehicle and any trailer it is towing. GCWR minus GVWR represents the allowable weight for the towed vehicle.
Gross Vehicle Weight (GVW):
GVW is the actual weight of a fully loaded vehicle (that is, vehicle, cargo, liquids/fuels, passengers, towed vehicles, tongue weight etc.) The GVW must not exceed the GVWR.
Gross Axle Weight (GAW):
This is the actual weight of a fully loaded vehicle carried by a single axle. Due to the many ways that weight can be distributed within an RV, GAW often can provide a false sense of security. Even though the weight of the total axle may be within the axle's rating, it may be overloaded on one side.