RV Glossary
Browse RV and towing terms
Browse RV and towing terms with practical definitions and related concepts used throughout our towing-capacity pages.
A
Axle Ratio
Axle ratio describes how many times the driveshaft rotates for one full wheel rotation, which affects towing power and fuel economy. Higher axle ratios generally improve towing performance.
B
Bearing Grease
Bearing grease lubricates trailer wheel bearings to reduce friction, heat, and wear during travel. Proper bearing maintenance is essential for safe and reliable towing.
Breakaway Switch
A breakaway switch activates a trailer’s brakes if it becomes disconnected from the tow vehicle. It is a required safety component on many towable RV setups.
F
Fifth Wheel Hitch
A fifth wheel hitch is a specialized hitch mounted in the bed of a pickup truck for towing a fifth wheel RV. It provides greater stability and tighter turning than a standard rear hitch.
G
GCWR
Gross Combined Weight Rating, or GCWR, is the maximum total allowable weight of a tow vehicle plus the RV or trailer it is pulling. It is one of the most important towing specifications to understand before buying or towing an RV.
GVWR
Gross Vehicle Weight Rating, or GVWR, is the maximum allowable weight of an RV including cargo, fluids, and passengers. Staying within GVWR is essential for safe handling, braking, and compliance.
H
Hitch
A hitch is the connection point that attaches a trailer or RV to a tow vehicle. Different hitch types are designed for different trailer sizes, towing capacities, and towing setups.
Hitch Weight
Hitch weight is the amount of weight a trailer places on the hitch of the tow vehicle. It is closely related to tongue weight and helps determine whether a towing setup is safe.
T
Tongue Weight
Tongue weight is the downward force a trailer places on the hitch of the tow vehicle. Proper tongue weight is critical for towing stability, steering control, and safety.
Tow Bar
A tow bar is a device used to connect a vehicle behind a motorhome for flat towing. It allows the towed vehicle to roll behind the RV without using a trailer.
Tow Dolly
A tow dolly is a small trailer that lifts the front wheels of a vehicle off the ground for towing behind a motorhome. It is commonly used when a vehicle cannot be flat towed.
Tow Rating
Tow rating is the maximum trailer weight a vehicle can safely pull as specified by the manufacturer. Matching an RV to the correct tow rating is essential for safety and performance.
W
Weight Distribution Hitch
A weight distribution hitch helps spread trailer weight more evenly across the tow vehicle and trailer axles. It improves towing stability, braking, and overall handling.
Wheel Bearing
Wheel bearings allow trailer wheels to spin smoothly on the axle while supporting load and movement. They require regular inspection, lubrication, and maintenance.