RV Towing Tips

As an RV Sales Consultant, I am frequently asked questions relating to the weight of RVs, towing capacity of trucks, and other questions relating to the weight and loading of RVs, trucks and trailers. In response to these many questions I find I am sharing the same information and advice with one RV'er at a time. The similarity of the questions has prompted me to show this article so that I can share my education and experience with all of you.

I am a staunch advocate of RV SAFETY. A critical safety issue all RV'ers need to become more informed about is "Weights & Balance". But, just what is meant by "Weights and Balance"? Why is this term becoming of more interest to RV'ers? The answers are fundamental; Saving you time, money, and ensuring your safety.  Pretty solid reasons for most of us to realize the importance of Weights and Balance.

"Weights & Balance" pertains to the weight of an object with all of its component parts, and the distribution of that weight. Although weight and balance applies to many fields, I will limit the discussion to RVs. Building on the fundamental definition the discussion will include matters such as Gross Vehicle Weight Rating (GVWR), Gross Combined Vehicle Weight Rating (GCWR), Axle Weights, Axle Weight Rating (AWR) and more.
Proper loading of, and weight distribution in, your trailer or 5th wheel, can prevent premature tire failure, suspension problems, broken axles, burned-up transmissions or differentials, and other breakdowns. In addition to the cost of repair parts and labor, there could be expensive unscheduled stays in hotel/motel rooms, and the associated meals, towing, etc. Of course, the worst case scenario would be a wreck resulting from a blowout, or perhaps loss of control.

There is a difference between "load" (actual weight applied) and "load rating" (maximum engineered design load limit). Gross Vehicle Weight Rating (GVWR) is determined by the manufacturer in the design of the unit. GVWR cannot be changed; that is to say, the addition of heavier components does not change the legal GVWR of your vehicle. Any load exceeding these manufacturer's rating values is both unsafe and illegal; and perhaps immoral, for in doing so, you consciously put other people at risk,
including yourself.
If your intended purchase is too heavy for your tow vehicle or chassis, you will be faced with continued frustration, frequent expensive repairs, instead of the fun and relaxation that the RV Lifestyle should offer.

The following terms that we are going to be talking about, do not have consistent usage in the RV marketplace as a rule. Some RV Sales people may use different terms then others. A discussion with the RV salesperson to understand exactly how they are using these terms should be looked into.

UVW (Dry Weight:) Unloaded Vehicle Weight for trailers. Term most used is the "dry weight" and is the empty weight of the trailer. Dry weight may or may not include the weight of appliances, slide outs, propane tanks, spare tire, or battery. Check and make sure you are getting the right information.

Wet Weight:  is the weight of the trailer, and should, but may not, include the weight of the LPG (propane) in the tanks, and fresh water. (Water weight is 8.34 lbs./U.S. Gallon, so a 100 Gallons weighs 834 lb..)

TGVWR (Trailer Gross Vehicle Weight Rating:) is not a common term (and won't be found on any label or in any owner's manual), but used here to distinguish between Tow Vehicle GVWR and Trailer GVWR).
In most cases, many RV Dealers and Manufacturers will use the term GVWR, (not TGVWR). This term refers to the dry weight of the RV, plus the cargo carrying capability of the RV  Example; Dry weight of an Rv weights out at 5,000 lbs, and the GVWR is 7500 lbs, which means that the cargo carrying capabilty of the Rv is (7,500lbs - 5,000lbs)  = 2,500lbs

Many people are under the impression that if their truck is rated for 6500lbs GVWR, and if the trailer they are looking at has a GVWR rating of 7,000lbs, that they can't pull that trailer, because it is over what their truck is rated for. However, that may not be true, and here's why.  Let's say that the dry weight of the RV is 4,000lbs, that means it has a cargo carrying capability of (7,000lbs - 4,000lbs) =3,000lbs cargo carrying capacity.  Can this truck pull this trailer? Sure it can, and here's why.
Here's a rule of thumb; take the dry weight of the RV,(in this case 4,000lbs) add approx 2,000lbs,
which = 6,000lbs. The question here is this; are you going to put more then 2,000lbs of weight in your RV and truck combined, including people and gas in the truck, and the RV loaded up? If the answer is no, then you still have 500lbs left over. A little common sense here is all you need. Now, if you are putting an 800lb quad in the box of the truck, you are over. In this case you have 2500lbs to work with.

Now, just to be clear here, the GVWR of your vehicle does not always refer to what weight it can tow.
It may be used as a rule of thumb, but I have a book that tells what weight a vehicle can tow.
And it has it broken down for towing a tag along trailer, and a fifth wheel, and the numbers can be different. So, ask the right questions, if the RV sales person you are talking to doesn't know, find someone who does. This is a safety issue, you need to know this before hooking up.

Axle Ratio of Tow Vehicle
I'm not going to get too much into this, other then to say that the axle ratio of a tow vehicle can be a
determining factor in how much weight your vehicle can pull. Check with the RV sales person, and if they can't help you, find someone who can guide you correctly in this matter. 

 

Other Things to Consider
Here is a Rule of Thumb Chart used in determining how long a trailer you should be pulling with your vehicle:

For the first 110" of wheelbase, this allows you 20' of trailer.
For each additional 4" of wheelbase, this gets you 1' more of trailer.

Here is a chart:

(This guideline was first used by the RV Consumers Group in the US.

Tongue Weight and Pin Weight
Travel trailer hitches should carry 9-12%(tongue weight) of the trailer's loaded weight, and 5th wheel hitches should carry 15-18%(Pin Weight) of the trailer's loaded weight. Other sources use numbers as high as 20-25% for 5th wheel hitches. So a 5th wheel that weights out at 10,000 lbs, should have a hitch weight of (using 18%) no more then 1800 lbs..
Hitch Weight Distribution:
Most travel trailers should use a load leveling (weight distribution) hitch.(often called an equalizer hitch and bars). Before hooking up, measure the distance from some convenient reference point on the tow vehicles front and rear bumpers to the ground. Then connect the trailer and start loading the hitch torsion bars one chain-link at a time, keeping the chains equal on each side. As the load on the torsion bars is increased, the rear of the tow vehicle comes up and the front goes down. When the front and rear bumpers are as close to the reference measurement as you can get (and it should be within a half-inch at the front bumper) the hitch is tensioned correctly.
Wheel Base of Tow Vehicle
A self-contained unit's wheelbase to length ratio can be used to judge how well a vehicle will ride and handle. A short wheelbase makes for easier maneuvering while a longer wheelbase increases high speed stability and ride comfort. However, when comparing Length Overall (LOA) to wheel base length, a long trailer on a short wheel base towing vehicle is not desirable.. Dividing the wheel base (Inches) by the vehicles length (Inches) it is favorable to have a ratio of 0.54 (54%) or more. Long haul busses, such as Greyhound buses, have a 0.66 ratio for both comfort and SAFETY. Yet another issue is the center of gravity. The higher the CG the less stable the vehicle will be in turns and curves, or in cross winds. 

No matter how many times you may have gotten away with improper vehicle overloading in the past, or what you may have seen others doing, to be SAFE you need to respect the engineering design limits. These ratings are based on a lot more than what I can cover in this article, but the bottom line is to follow the weight ratings published by the manufacturers. Be Safe, Don't Be Sorry. Follow Them!

Conclusion:
Now, all you need to know when you come in to talk about buying an RV is, what is your truck, suv, or van, rated for towing weight? If you do not know this information, fill out the form below, and I will refer to a reference book which gives me the ratings for most vehicles.

In determining this information, I need to know the year, make, model, axle ratio, if it is an automatic or standard transmission, short/long box, crew/extended cab (if a truck), size of motor, and does it have a towing package.(Receiver hitch already on the vehicle)
I have seen too many times where people go out and buy a truck, to find out when they come in to purchase an RV, that they can't pull the trailer or 5th wheel that they want to purchase.  If you are looking at purchasing a new truck and an RV, I highly recommend that you pick out the type of RV you what to purchase before purchasing the truck.

Note: The information given in this article is based on information from a number of different sources, and is considered to be fairly accurate.

What Can I Tow?