I don't believe there is an RV-related subject that causes more arguments than RV weight, unless maybe it's the argument over trailer vs. 5th wheel vs. motor coach. Between the cryptic way that RV weights are reported by the manufacturers, the lack of clear standards by the DOT and the often deliberate misinformation spread by RV dealers; RV weights are confusing at best. We recently purchased a new RV - a process that finally prompted me to attempt to fully understand this subject. The following is what I learned, and in my humble opinion, an authoritative explanation of what the truth really is.
Let's start with the 2 stickers that are required by law on every RV sold in America. The RV manufacturer is required to include a Weight Sticker on the RV that details all the important weight ratings and maximums. This sticker is usually located on the inside of one of the kitchen cabinet doors. The other sticker required by law is a tire capacities sticker. This is usually outside the RV, somewhere near the hitch on tow able RV's. It can be on the inside door frame, near the engine compartment or on the inside of the service door for motor coaches. In addition to these 2 stickers on the RV, you'll also need the ratings from your tow vehicle if working with a tow able.
The RV's weight sticker displays all of the most important weights as they apply for your RV. The information on this sticker has changed over the years, but it should contain at least some combination of the following:
All of these may not be on your sticker since some only apply to certain RV classifications. In addition, there may be other weights listed. In addition to the RV's sticker, you'll need to understand the weight rating of your tires. For towables you'll also need to get the ratings from your tow vehicle. This sticker is usually found on the door frame of the driver door, or can be located in your owner's manual. It contains many of the same ratings as they apply to the tow vehicle only.
By this point I was already beginning to feel the effects of information overload. Did I really need to fully understand all of these numbers as well as the mathematics involved? Was it possible to reduce this down to a manageable level and make intelligent, informed decisions? I finally worked it out to a few basic formulas that allowed me to fully comprehend all the important information. With that in hand, we were able to make an informed purchase for our new RV.
Let's start with the gross weights since these are ratings that are difficult to modify. It's easy to adjust the amount of cargo you're carrying, or reduce the amount of fresh water in the tank. The gross weights are fixed however, and short of making major modifications to the RV, are absolute barriers.
In our case we had already decided on a large travel trailer for our new RV. I don't intend this article to be a debate in the age-old travel trailer vs. 5th wheel vs. coach argument. Suffice it to say we have very good reasons for choosing a travel trailer over the other classifications. With this is mind, let's look at the all-important gross weights.
The most important weight to us were the:
These are the ratings we couldn't exceed regardless of how we configured the RV or what we carried as cargo. There are very good engineering and legal reasons for not exceeding these ratings, no matter how you slice them. In my opinion, these are the most important ratings to consider when buying a new RV, regardless of what the RV dealer may try to convince you of.
In our search we ran across both honest dealers and those that were not so honest about RV weight ratings. The majority of the time however, the dealers were neither. They simply didn't understand these weight ratings and were either misinformed or had no clue how to truly help. Of the dealers that either weren't properly knowledgeable or those that were downright dishonest, most tried to convince us that the only weight that mattered was the UVW and whether or not that was at or below our tow vehicle's max towing capacity. In addition, I don't know how many dealers tried to convince us that these weight ratings have a little "fudge factor" engineered into them.
One of the smartest things we did was speak to our attorney before making a purchase. He informed us that exceeding any of the weight ratings of the RV or the tow vehicle was nothing more than a negligence lawsuit waiting to happen. If it's proven that you exceeded the manufacturer's ratings in any way, it can easily be argued that constitutes negligence on your part in the event of an accident. That can lead to problems ranging from very large settlement amounts to even the possibility of your insurance company refusing to pay the claim due to the negligence on your part. Simply put, don't exceed these weights under any circumstances.
The best way to look at it is to take each and every maximum rating and make sure you are under every one of them. Especially after you are loaded, fueled and ready to get on the road. Often, the only way to do this is to load up your rig and head for the nearest truck stop with a scale. Weighing your rig and understanding the weights you get are key to a safe outcome.
Weighing your rig is easy and costs very little compared to the alternatives. Load your rig with everything your think is necessary, fill it with fuel and drive to your nearest truck stop with a scale. In order to get enough information to calculate all the primary weights, you'll need to get two weighings.
First, weigh the entire rig as being towed, or in the case of a coach with chase car attached. Just make sure both your TV (Tow Vehicle) axles and the TT (Travel Trailer/5th Wheel) axle(s) are on 3 separate weighing pads. That will give you weights for your steer axle, your drive axle and your TT or chase car axle(s). Next, take the TT or chase car and "drop" it in the parking area so you can come back and weigh just the TV or coach; again making sure the steer axle and drive axle are on different pads to get 2 separate weights. From these 2 weighings you can calculate all the weights you need.
GCVW (Gross Combined Vehicle Weight) is the total weight of the first weighing. It is important that you do not exceed your TV's rating or your coach rating on this. If you do, you could be find yourself facing that law suit for negligence I mentioned earlier, not to mention that fact that it's unsafe. You coach or TV are only engineered to handle that much weight and you could face brake failure, tire failure of other issues if this weight is exceeded.
TV GVW (Tow Vehicle's Gross Vehicle Weight) is the total of the second weighing. Like the GCVW, it is important to not exceed your TV or coach's max rating.
Axle weights. Each of your TV's axles have a max rating, as does your TT. From the individual weights of the axles in both weighings you can tell if you're exceeding any of the max ratings for your axles. Pay particular attention to your TV's drive axle from the first weighing. It will be heavier than it is in the second weighing because of the tongue weight of the TT or chase car.
TT GVW (Trailer's Gross Vehicle Weight). For this one you need to do a bit of math, but it's not difficult.
TT GVW = GCVW - TV GVW
Both your TT and your hitch have a max rating for this. This weight must not exceed either the GVWR of the TT as found on the sticker, or the Max Towing Capacity of your TV. Hitches also have 2 max ratings, one for the max towing weight (this weight) and one for the weight of the trailer tongue.
Tongue Weight. For this one you need to do a bit of math as well:
Tongue Weight = GCVW - TV GVW - TT Axle Weight
This needs to be within the max tongue weight rating of your particular hitch.
One last thing ... your on tires both your TV and TT. Many people overlook their tire load rating. The load rating is found on the tires sticker and written on the side of your tires and should not be exceeded. Personally, I want plenty of safety margin here. If you run your tires very close to their max load rating it will wear the tires prematurely. More importantly, if you experience a blowout of 1 tire on a tandem axle, the other tires are now carrying considerably more weight than they are rated to carry; especially the ones on the same side as the blow out. It is possible to damage multiple tires in a situation like this before you can even get the rig stopped.
If you pay the most attention to your gross weight ratings, the rest of the capacities seem to take care of themselves. Not that the others aren't important, it just seemed easier for me to deal with the gross ratings and let the other level out as needed. Since we're full-timers that travel a lot, I weigh often. It will surprise you how much "cargo" you accumulate as time goes by.
It's easy to weigh at commercial truck stops and the cost is usually reasonable. Most truck stops will only charge you full price for the first weighing, then a small additional price for the second weighing. The last time I weighed at a CAT scale at a Love's truck stop, they charges me $7.00 for the initial weighing and only $1.00 for the second one. A small price to pay for peace of mind.
Phil & Karen King are full time RV'ers. They travel 12 months a year and have extensive RV'ing experience. They are the founders of CoolRVToyz.com, a web site dedicated to bringing the latest, and coolest gadgets to the RV lifestyle, including The Ultimate RV Parks List & Campgrounds Directory, the largest, most accurate and most complete camping Campgrounds Directory available. Best of all, it's fully downloadable into your favorite GPS or trip planning program.