Recently, I decided to learn about towing terms so I would know what I was doing. After towing a half dozen times I began to feel I was allowing myself to remain ignorant. Hauling at least 10,000 pounds down the road at 70 mph should give you pause to think about the responsibility you have to know you are doing it right and safe. For me it was the realization that my wife, 5 year daughter and 3 year old son where in the truck with me. I could never forgive myself if they got hurt because of my wanton ignorance or neglect. Here is what I discovered and learned.
Ford defines base curb weight as the weight of a vehicle with all standard equipment plus all fluids at capacity and a full tank of fuel. It does not include any optional items, passengers or cargo. For example if A/C is not standard, the A/C system weight is not included in the base curb weight if you have that option. Neither was that fancy leather interior with dual power seats.
Passengers are, well, passengers. Pretty self explanatory.
Cargo weight, as the name implies, are all items you carry in or on a vehicle that are not passengers. Think of anything added to your truck as cargo. Brush guards, bed cap, etc add weight and reduce capacity.
The maximum combined passenger and cargo weight is called Payload. Can you see why payload capacity statements are misleading to the uninformed yet? Your truck is billed as having 1200 pounds payload capacity. Now your buddy is with you and you two add up to 500 pounds. You also have some stuff added to your truck like a brush guard and your hitch in in the receiver. They add up to 125 pounds. 1200 - 500 - 125 = your real payload capacity on that trip of 575 pounds. 575 is a lot less than 1200.
GVWR, GVW GAWR, GAW, GCWR, GCW
These are six acronyms for six important pieces of information all related to weight. They are similar in name, but are individually important. Three of them are ratings and three of them are actual real world weights that will vary with every trip. As a result, some confusion is to be expected until or unless you understand them and what they mean.
As a driver towing a trailer or carrying a load you must be mindful of these terms as there are three weights that must never, ever, be exceeded. Exceeding these weight limits puts you, your passengers and every other driver on the road at risk of property loss and/or damage, injury or death. And the responsibility to be under the limit is solely on the driver's shoulders. You can, and should, expect your insurance company to say you're on your own if you are over the limit and have an accident.
GVWR is your Gross Vehicle Weight Rating. This is the maximum weight your pickup can weigh with all it's passengers and cargo in and/or on it. If you are towing a trailer, the trailer will also have its own GVWR. You should know it as well.
GVW is your Gross Vehicle Weight. This is the actual weight of your vehicle at any given time. This weight must NEVER exceed the GVRW. If a trailer is attached the weight of the hitch and the tongue weight must be added with your tow vehicles weight. For example, if your truck weights 6000 pounds and you hitch and tongue weight total 550 pounds, your truck now weights 6550 pounds.
GAWR is your Gross Axle Weight Rating. Ever pickup has a front axle and a rear axle and each is rated separately. It is the total amount of weight that a given axle is rated to carry.
GAW is your Gross Axle Weight. This is the actual weight carried by a given axle at any given time. The load carried on any single axle must NEVER exceed that specific axles GAWR. If a trailer is attached the weight of the hitch and the tongue weight must be included on the rear axle. For example, the truck above carries 40% of it's weight (2400 lbs) on the rear axle. The rear axle is rated to say 3500 pounds. Now add the 550 hitch/tongue weight, the weight of passengers (let's say 500 pounds) and a bunch of stuff you are carrying in the bed (say 200 pounds). So 2400 + 550 + 500 + 200 = 3560. Getting close.
GCWR is your Gross Combined Weight Rating. This is the maximum weight of your pickup added to the maximum weight of your trailer including all cargo and passengers. If you add the truck GVRW and the trailer GVWR and they add up to more than the GCWR, then the truck and trailer combo is a poor match.
GCW is your Gross Combined Weight. This is the actual total weight of your pickup with the trailer loaded and attached. The GCW must NEVER exceed the GCWR.
The last piece of the puzzle that must be observed is the maximum loaded trailer weight limit for your tow vehicle. Do not exceed this limit either. You can find this in the tow vehicle manufacturers towing guide, the owners manual or can be obtained from the manufacturer or from their representatives.
These weight ratings are often a little difficult to source. They are rarely all in one place. The best place to find your GCWR and GAWR is in the drivers door jamb of any vehicle rated to tow. You will find a safety certification label with the GCWR and the GAWR split out for the front and rear axles. A word of caution on these two ratings. Getting these numbers from a book may give you incorrect numbers for the vehicle you have or are looking at. The sticker in the jamb should be the details for that trucks configuration. The GCWR is also usually found in a tow vehicle manufacturers towing guide, the owners manual or can be obtained from the manufacturer or their representatives.
The actual weights are easy to measure if you have access to scales and this is the preferred method, but you can get pretty close with honest and realistic estimations of your weights above and beyond the base curb weight of a vehicle. You should be able to get close enough to safely assess if the truck you have or are looking to buy is enough tow vehicle for what you are going to tow.
Source: Some of the above is sourced from the 2011 Ford Towing Guide.