Why these numbers matter
Every tow vehicle and trailer has a set of weight ratings that define the boundaries of safe operation. These aren't suggestions — they're engineering limits set by the manufacturer based on braking distance, suspension capacity, frame strength, and tire load. Exceed any one of them and you've transferred the risk from the engineer who designed the system to yourself.
The common mistake is treating towing capacity as the only number that matters. It isn't. You can be within your tow vehicle's maximum tow rating and still be over GVWR, over a GAWR, or over payload. Each of these is an independent limit that must be checked independently.
The key ratings — defined
Gross Vehicle Weight Rating
The maximum total weight your tow vehicle is designed to handle — the vehicle itself plus everything in it: passengers, fuel, cargo, and the tongue or pin weight of the trailer. Your TV's GVWR is on the door jamb placard. Exceeding it stresses the frame, brakes, and suspension.
Gross Combined Weight Rating
The maximum total weight of the loaded tow vehicle plus the loaded trailer together. This is the system limit — even if the TV and trailer are individually within their own limits, the combination must stay under GCWR. GCWR is specific to your tow vehicle's engine, transmission, and axle ratio.
Gross Axle Weight Rating
The maximum weight each axle assembly is designed to carry, as measured at the tires. Both the tow vehicle and trailer have GAWRs — each axle has its own. Tongue or pin weight adds directly to the TV's rear axle load; this is the most commonly exceeded axle on tow vehicles.
Gross Trailer Weight
The actual total weight of the trailer as it sits, fully loaded — water, gear, propane, and all. Not the trailer's GVWR (the limit) — GTW is the measured reality. GTW must be within the trailer's GVWR, the TV's tow rating, and the GCWR.
Tow Vehicle Payload Capacity
GVWR minus the vehicle's curb weight (how much it weighed empty from the factory). Payload is what's left for passengers, cargo, and tongue/pin weight. This number is often on a yellow sticker inside the driver's door. It's typically 1,000–2,500 lbs on a half-ton, 2,000–4,000 lbs on a ¾-ton or 1-ton — and it fills up faster than most owners expect.
Tongue Weight (travel trailer / toy hauler)
The downward force the trailer exerts on the hitch ball, measured at the hitch. Should be 10–15% of the trailer's GTW for conventional trailers. Too little causes trailer sway; too much overloads the TV's rear axle and reduces front axle steering control. Tongue weight counts against TV payload.
Pin Weight (fifth wheel)
The downward force a fifth wheel exerts on the kingpin receiver in the truck bed. Functionally the same as tongue weight but typically higher — 15–25% of GTW — because of where the hitch point sits relative to the rear axle. Pin weight counts against payload and rear axle GAWR.
Cargo Carrying Capacity
For the trailer: GVWR minus UVW (factory weight). The maximum weight of water, passengers, gear, and supplies you can add. A full 40-gallon fresh water tank is ~330 lbs. Many RVers are already over their trailer's CCC before they add gear.
How payload fills up — faster than you think
Payload is the most misunderstood limit in towing. People focus on max tow rating (a large marketing number) and ignore payload (a small operational number). Here's how a typical half-ton truck's payload disappears on a family towing trip:
Example: Half-ton truck, 1,800 lb payload
Tongue weight (15% of 8,000 lb trailer)
+
1,200 lb
Total used: 2,160 lb
— 360 lbs over a 1,800 lb payload
The tow rating trap
A truck rated to tow 10,000 lbs does not mean you can safely tow a 10,000 lb trailer with four people, gear, and a full fuel tank. Maximum tow rating assumes the truck is at curb weight with only a driver. Every pound of passengers, cargo, and fuel reduces how much trailer you can actually tow.
The rear axle problem
Tongue weight and pin weight don't just count against your total payload — they land specifically on the rear axle of the tow vehicle. A fifth wheel with 1,800 lbs of pin weight puts all 1,800 lbs on the truck's rear axle GAWR. Combined with cargo in the bed, passengers, and the rear axle's share of the truck's own weight, the rear GAWR is the most commonly exceeded rating in RV towing.
The only way to know your actual rear axle load is to weigh the truck at a certified scale — with the trailer hitched and everything loaded as you'd travel.
RigIQ
RigIQ tracks per-axle corner weights for both your trailer and your tow vehicle independently. Enter your TV's GVWR and per-axle GAWRs in Garage → Tow vehicle specs. The Weights tab compares each axle against its limit — including the rear axle that bears your tongue or pin weight.
The numbers to verify before every trip
- TV rear axle ≤ rear GAWR — weigh with trailer hitched and fully loaded
- TV total ≤ TV GVWR — includes tongue/pin weight
- TV + trailer total ≤ GCWR — the system limit
- Trailer total ≤ trailer GVWR — weigh fully loaded
- Each trailer axle ≤ its GAWR — per-axle, not just the total
- Tongue/pin weight = 10–15% (travel trailer) or 15–25% (fifth wheel) of GTW
Where to find your ratings
- Tow vehicle GVWR, GAWR, payload — yellow sticker or white Federal Certification label inside the driver's door jamb
- GCWR and max tow rating — owner's manual towing guide, or the manufacturer's towing guide for your specific year, engine, and axle ratio
- Trailer GVWR and GAWR — Federal Certification label inside the trailer's entry door
- Trailer UVW and CCC — same label, or manufacturer's spec sheet for your model
Axle ratio matters
GCWR and max tow rating vary by engine, transmission, and axle ratio — two identical-looking trucks with different axle ratios (3.31 vs 3.73) can have meaningfully different tow ratings. Always confirm against the towing guide specific to your VIN, not a generic trim spec. Ford, Ram, Chevy/GMC, and Toyota all publish annual towing guides by model and configuration.
Continue reading
Track every limit in one place
Enter your tow vehicle and trailer specs in RigIQ. Weigh at a certified scale, enter the readings, and RigIQ flags every limit — GVWR, GAWR, tongue weight — instantly.