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TL;DR
- Three ratings limit every tow: GVWR (the loaded truck), GAWR (each axle) and GCWR (truck plus trailer). GVWR and GAWR are on the door-edge certification label.
- Tongue weight counts against the truck’s payload. Ford uses 10% of the loaded trailer for conventional trailers and 15% for 5th-wheels, so a 5,000-lb trailer puts about 500 lbs on the hitch.
- Hitch class is a ceiling, not a guarantee. A Class 3 receiver tops out at 8,000 lbs weight-carrying (12,000 with weight distribution), and the lowest-rated part of the rig sets the limit.
- A weight-distribution hitch is required when the trailer exceeds the receiver’s weight-carrying rating. On an F-150, Ford sets that line at 5,000 lbs.
- Most states require trailer brakes somewhere between 1,500 and 4,500 lbs, and electric brakes need a brake controller. Proportional controllers match trailer braking to how hard the truck is stopping.
- Towing mirrors are needed once the trailer blocks your view. Oregon and California both require a view at least 200 feet behind the vehicle.
At a Glance
| The problem | What solves it | The number to check |
|---|---|---|
| Truck squats at the back and steering feels light | Weight-distribution hitch | Your receiver’s weight-carrying rating, printed on its label |
| Trailer can’t stop itself | Trailer brakes plus a brake controller | Your state’s brake threshold (1,500–4,500 lbs) |
| You can’t see past the trailer | Towing mirrors | A clear view at least 200 ft behind you |
| Trailer wags or sways | More tongue weight first, then sway control | Tongue weight of about 10% of the loaded trailer |
| Not sure the truck can carry it | A scale ticket and the payload checker | GVWR, rear GAWR and GCWR |
GVWR, GAWR, GCWR and Payload: Where the Numbers Come From
Ford’s 2026 RV & Trailer Towing Guide defines the terms most makers use. Base curb weight is the vehicle with a full tank of fuel and standard equipment, but no passengers, cargo or optional equipment. Payload is GVWR minus base curb weight: the most passengers and cargo the vehicle is designed to carry. When towing, the trailer’s tongue load (or 5th-wheel king pin weight) counts as cargo. GVWR caps the loaded truck, GAWR caps the load on each axle, and GCWR caps the loaded truck and loaded trailer together.
Federal rules decide which numbers are printed on the truck. 49 CFR 567.4 requires a certification label on the driver’s door hinge pillar, latch post or door edge showing GVWR and the GAWR of each axle. It doesn’t require curb weight. FMVSS 110 requires a tire and loading placard on the driver-side B-pillar stating that “the combined weight of occupants and cargo should never exceed” a set number of pounds for that exact vehicle as built. GCWR isn’t on either label; it comes from the owner’s manual or the towing guide.
Ford’s maximum trailer ratings assume a truck with only mandatory options, no cargo, and a 150-lb driver and 150-lb passenger. Every option, passenger and accessory added after that comes off the maximum. Ford’s chart figures are calculated with SAE J2807, the industry procedure for setting GCWR and trailer weight ratings.
Tongue Weight: The Number That Links Truck and Trailer
Tongue weight is the part of the trailer’s weight pressing down on the hitch. Ford’s rules: for trailers up to 2,000 lbs, tongue load must not exceed 200 lbs; for conventional trailers over 2,000 lbs, it is 10% of the loaded trailer weight; for 5th-wheel trailers, king pin weight is 15%. Ford’s worked examples: a 5,000-lb conventional trailer carries 500 lbs on the hitch, and an 11,500-lb 5th-wheel puts 1,725 lbs on the king pin. Sherline, which makes tongue-weight scales, gives a wider range of 10–15% for most bumper-pull trailers, calls 12% ideal, and says 5th-wheels can carry up to 25%.
Both directions cause trouble. Too much tongue weight presses the rear down and can lift the front wheels until steering and braking suffer. Too little reduces rear-wheel traction and causes instability, which Ford describes as tail wagging or jackknifing. The fix is loading, not hardware: Ford says to move cargo rearward if tongue weight is above the limit, forward if below, and to put about 60% of the trailer’s cargo in the front half.
To measure it, Ford says to place only the tongue on a scale at hitch-ball height. For axle weights, weigh the loaded truck and trailer at a commercial scale: front wheels on the scale for front GAW, all four truck wheels for the truck total, then subtract to get rear GAW. See tongue weight scales for the tools.
Hitch Classes and Receiver Ratings
| Class | Receiver | Weight-carrying (GTW / tongue) | With weight distribution |
|---|---|---|---|
| Class 1 | 1-1/4 in | Up to 2,000 / 200 lbs | — |
| Class 2 | 1-1/4 in | Up to 3,500 / 350 lbs | — |
| Class 3 | 2 in | Up to 8,000 / 800 lbs | Up to 12,000 / 1,200 lbs |
| Class 4 | 2 in | Up to 10,000 / 1,000 lbs | Up to 12,000 / 1,200 lbs |
| Class 5 Xtra Duty | 2 in | 16,000–17,000 / 2,400–2,550 lbs | 17,000 lbs |
| Class 5 Commercial Duty | 2-1/2 in | 18,000–20,000 / 2,700 lbs | 18,000–20,000 lbs |
These are CURT’s class ceilings. Individual hitches are often rated lower: Ford says each of its factory receivers carries a label giving both its weight-carrying and weight-distributing capacity. Ford’s F-150 receiver chart lists 5,000 lbs / 500 lbs weight-carrying and up to 13,500 lbs / 1,400 lbs weight-distributing (with the Tow/Haul Package and Max Tow Axle). CURT’s rule is that towing capacity is always limited to the lowest-rated component: hitch, ball mount, ball, coupler, trailer or vehicle. Full detail is in trailer hitch classes explained.
Weight-Distribution Hitches: When They Are Required
A weight-distributing hitch attaches to the receiver and uses spring bars (Ford calls them equalizing arms), tensioned with chains or brackets, to lift some load off the truck’s rear axle and shift it to the front axle and the trailer’s axles. It doesn’t reduce tongue weight. Sherline notes it only redistributes it. When one is needed is set by ratings: Ford says not to exceed 5,000 lbs on an F-150 without weight distribution, and lists it as required for certain Class III and all Class IV applications. Ford’s setup method compares front fender height unhitched (H1) and hitched without bars (H2), then tensions the bars to restore a set share of the drop. For the F-150, Super Duty pickups and Expedition that share is 50%, so a 1-inch drop from 37 to 38 inches gives a 37.5-inch target. Sizing and bar types are covered in best weight distribution hitches.
Trailer Brakes and Brake Controllers
Trailer brakes come in three types. Electric brakes use a magnet in each drum powered by a controller in the tow vehicle. Electric-over-hydraulic brakes use an electric pump to pressurize the trailer’s own hydraulic system. Surge brakes use a master cylinder in the trailer coupler that is pushed on when the trailer runs up against the truck. Ford says the truck’s hydraulic system must never be connected to the trailer’s. Oregon DOT notes that surge brakes aren’t legal in some states.
Dexter, a major trailer-axle maker, says a proportional (inertial) controller varies current to the brakes with the tow vehicle’s deceleration, while electronic timing controllers don’t. Dexter says a controller should deliver about 2 volts when the pedal is first pressed, rising gradually to 12 volts. A controller that jumps straight to high voltage gives harsh braking and possible wheel lockup. Dexter rates each brake magnet at 2.5 amps (7-inch brakes) or 3.0 amps (10- to 12-1/4-inch brakes), so a tandem-axle trailer with four 12-inch brakes draws about 12 amps. It calls for at least 12 AWG hookup wire for that trailer with under 30 feet from hitch to axle, and 10 AWG from 30 to 50 feet.
| State | Trailer brakes required at |
|---|---|
| California | 1,500 lbs gross weight for trailer coaches and camp trailers (Vehicle Code §26303) |
| Idaho, Nevada | 1,500 lbs |
| Colorado, Georgia, Indiana, Virginia | 3,000 lbs |
| Florida, Michigan, Pennsylvania, Washington | Over 3,000 lbs |
| Texas | Over 4,500 lbs |
The table is from RVIA’s August 2017 summary of state codes, and RVIA says it isn’t legal advice. Confirm the current rule with your own state and every state you’ll drive through. Many states also require a breakaway system: a battery on the trailer and a switch pulled by a cable that applies the brakes if the trailer separates. California Vehicle Code §26304 requires those brakes to hold the trailer for at least 15 minutes. Dexter’s schedule calls for testing the brakes and the breakaway system at every use. See best brake controllers.
Towing Mirrors: The 200-Foot Rule
Factory mirrors meet FMVSS 111, which requires flat (unit-magnification) outside mirrors on trucks. Those mirrors are sized for the truck, not for a trailer wider than it. State law sets the towing requirement: Oregon requires a clear view at least 200 feet to the rear at all times, and California Vehicle Code §26709 requires mirrors on both sides showing 200 feet behind any vehicle whose load blocks the rear view. Ford’s factory tow mirrors telescope outward when towing and slide back in when not. Clip-on and slide-on extensions are the aftermarket route. See best towing mirrors.
5th-Wheel and Gooseneck Hitches
A 5th-wheel or gooseneck hitch mounts in the pickup bed and puts the trailer’s pin weight over the rear axle rather than behind the bumper. Ford says the 5th-wheel hitch centerline should sit at least 2 inches forward of the rear axle centerline. CURT rates its 5th-wheel hitches up to 30,000 lbs and its goosenecks up to 38,000 lbs. Ford’s own 5th-wheel kits are rated at 20,000 and 35,000 lbs, and its gooseneck ball at 27,500 lbs on a 2-5/16-inch ball. The trade-off is clearance: Ford warns that short beds (5.5 and 6.5 ft on the F-150, 6.75 ft on Super Duty) leave less room between cab and trailer, and the combination must clear the cab in turns up to 90 degrees. Pin weight at 15–25% also uses much more payload than a bumper-pull trailer.
Trailer Tires, Wheel Bearings and Lug Nuts
Oregon DOT’s towing brochure, developed partly from NHTSA material, says to fit the tire size, type and load range shown on the trailer’s certification label, and to keep all trailer tires the same type and construction: don’t mix bias and radial. It also says to check tires for cracks and bulges before every trip, because trailer tires age even when they sit unused. Underinflation cuts load capacity and can cause overheating and blowouts. Dexter’s schedule for new axles is to check wheel-nut torque at 10, 25 and 50 miles, adjust brakes at 200 and 3,000 miles, and clean and repack wheel bearings every 12 months or 12,000 miles. Ford adds a stop after about 50 miles to recheck the hitch, lights and trailer lug nuts.
Altitude, Grades and Driving
Ford says to reduce GVW and GCW by 2% per 1,000 feet of elevation to match sea-level performance. At 7,000 feet, that turns a 14,000-lb combination into about 12,040 lbs. On long downgrades, downshift and use tow/haul mode rather than holding the brakes, which can overheat them. Ford also says not to tow a new vehicle until it has been driven at least 1,000 miles.
How We Rank Towing & Payload Equipment
Products on this hub are weighed against their manufacturer ratings (spring-bar and tongue-weight range, receiver class, brake count supported) and against owner-reported fit and reliability. We don’t buy, install or tow with this equipment ourselves. See how we rank and our affiliate disclosure.
Sources
- Ford — 2026 RV & Trailer Towing Guide — Definitions of base curb weight, payload (GVWR minus base curb weight), GVWR, GAWR and GCWR; tongue load counts as cargo; tongue load 10% (200-lb cap under 2,000 lbs) and 15% king pin weight; F-150 5,000-lb limit without weight distribution and receiver ratings; weight distribution required for certain Class III and all Class IV trailers; fender-height setup with 50% correction; 60/40 loading; brakes rated at GVWR not GCWR and separate brakes above 1,500 lbs; 5th-wheel hitch 2 in forward of axle; short-bed clearance; 2% per 1,000 ft altitude derate; 1,000-mile break-in; tow mirrors; sway response.
- 49 CFR 567.4 — Vehicle certification label requirements (Cornell LII) — The certification label must show GVWR and each axle’s GAWR and sit on the driver’s door edge, latch post or hinge pillar.
- 49 CFR 571.110 — FMVSS 110, Tire selection and rims; tire and loading placard (Cornell LII) — The B-pillar tire and loading placard states the combined weight of occupants and cargo the vehicle should never exceed.
- SAE International — J2807 Tow-Vehicle GCWR and Trailer Weight Rating Standard — SAE J2807 is the procedure used to set GCWR and trailer weight ratings.
- Sherline Products — Hydraulic Trailer Tongue Weight Scale: Instructions and Trailer Loading Guide — Tongue weight of 10–15% for bumper-pull trailers with 12% ideal and up to 25% for 5th-wheels; a weight-distribution hitch redistributes but doesn’t reduce tongue weight.
- CURT Manufacturing — Types of Trailer Hitches and Hitch Classes — Class 1–5 receiver sizes and weight-carrying and weight-distribution ratings; 5th-wheel up to 30,000 lbs and gooseneck up to 38,000 lbs; towing capacity limited to the lowest-rated component.
- CURT Manufacturing — How to Choose the Best Weight Distribution Hitch — TruTrack 2P friction and 4P spring-and-cam sway control.
- Dexter — Light Duty Axle Operation, Maintenance & Service Manual — Proportional vs timing controllers and the 2-to-12-volt output ramp; amps per brake magnet; hookup wire gauge by brake count and distance; breakaway testing at every use; wheel-nut torque checks at 10, 25 and 50 miles, brake adjustment at 200 and 3,000 miles, bearing repack every 12 months or 12,000 miles.
- RVIA — Trailer Brake Requirements: State Equipment and Road Use Law Summaries (08/2017) — State trailer brake thresholds, including 1,500 lbs in Idaho and Nevada, 3,000 lbs in several states and 4,500 lbs in Texas (as of August 2017).
- California Vehicle Code §26303 — Trailer coach and camp trailer brakes — California requires brakes on trailer coaches and camp trailers of 1,500 lbs or more gross weight.
- California Vehicle Code §26304 — Automatic brake application on breakaway — California requires trailer brakes to apply automatically on breakaway and hold the trailer for at least 15 minutes.
- Oregon DOT — Towing a Trailer: Being Equipped for Safety (developed in part from NHTSA material) — Surge brakes aren’t legal in some states; too little tongue weight causes sway; clear view 200 ft to the rear; extended mirrors for trailers wider than the tow vehicle; trailer tire type, load range, inspection and inflation guidance.
- California Vehicle Code §26709 — Mirrors — California requires mirrors on both sides showing 200 ft to the rear when a load blocks the rear view.
- 49 CFR 571.111 — FMVSS 111, Rear visibility (Cornell LII) — Factory outside mirror requirements for trucks and multipurpose vehicles.