What You Need to Know About Your Truck's Weight Ratings

Because pickup trucks are frequently used to tow and haul, there's perhaps no more important or confusing specification to consider when purchasing one than its weight ratings. Overloading a truck can lead to a dangerous situation, not just for you but others on the road as well. It can also lead to premature wear and tear or damage to the truck's powertrain, frame and running gear, as well as create future issues with your vehicle's warranty.

Here are the terms you need to know.

Curb weight: This term refers to the weight of the actual pickup, which should include a full tank of fuel, engine fluids (coolant, oil, etc.) and all standard equipment. When the original equipment manufacturer lists a vehicle's curb weight, it will not include optional equipment, and it could be a very different number from the exact vehicle you have in your possession. It is always a good idea to have your personal vehicles weighed to determine the real weight.  

Cargo weight: Cargo weight is any weight added to the curb weight, including cargo placed inside the cab or into the bed, optional equipment, and trailer tongue weight if you're towing. The easiest way to calculate your exact cargo weight is to weigh your truck loaded and unloaded, subtracting the former from the latter.

Tongue weight: Tongue weight refers to the amount of trailer weight pressing down on the trailer hitch. It is usually expressed in a percentage of total trailer weight, so when you see "10 percent tongue weight," that means 10 percent of the weight of the actual trailer weight you're going to pull. Too much tongue load could damage or decrease the effectiveness of the rear suspension, as well as cause the front wheels to lift, or get light, to the point where traction, steering response and braking can be severely impaired. Too little tongue weight can reduce rear-wheel traction and cause instability, leading to trailer sway or jackknifing.

Gross axle weight ratings: Each axle of your truck has a specific maximum load-carrying capacity determined by the manufacturer. The rating should never be exceeded. GAWR is the maximum rated carrying capacity; GAW is how much weight the axle is carrying at any given point in time (and that weight constantly changes).  Every vehicle should have a posted GAWR for each axle.

Gross vehicle weight rating:
The maximum allowable weight for a fully loaded pickup, including passengers, cargo and trailer tongue weight. A truck's gross vehicle weight (best measured by driving a loaded truck onto a truck-stop scale) must never exceed the GVWR.

Gross combined weight rating: The maximum allowable weight for a pickup pulling a trailer, including cargo and passengers that the truck can handle without risking damage. A truck's gross combined weight (measured by driving a loaded truck and trailer onto a scale) must never exceed the GCWR. In some states, you may be required to have a commercial driver's license if you tow more than 10,000 pounds.

It's important to know that a truck's brake system is typically rated for operation only at GVWR, not the maximum GCWR. Many states mandate trailers more than 1,500 pounds be equipped with separate electric or hydraulic brake systems that can be integrated with the truck, so the driver can control both the truck's and the trailer's brakes simultaneously or separately (see our story on trailer-brake controllers).

If you're wondering where you can find these specs for the truck you're considering, you should be able to find a truck's GVWR, GAWR and GCWR on the safety compliance certification label in the driver-side doorjamb and in the owner's manual.

Quick formulas to remember:

Curb Weight = Vehicle weight to include fluids, no passengers

Gross Vehicle Weight = Vehicle curb weight + Cargo weight + Driver + Passengers

Gross Combined Weight = Gross vehicle weight + Loaded trailer weight

© Cars.com 01/18/2013