By Skip Skipper, F119793
National Vice President, Eastern Area
Much has been said and written over the last several years regarding the importance of proper weight and balance of recreation vehicles, or more specifically in our case, motorhomes. This is a complicated issue, to be sure, but I will attempt to clarify it from a layman’s perspective.
FMCA has placed significant emphasis on this issue by providing an incentive to members who wish to participate in the coach-weighing program that is available at all international conventions and most area rallies. The weighing service is offered by the RV Safety Education Foundation (RVSEF), C5999, and was formerly a service of A’Weigh We Go. FMCA offers members a $15 supplement that is applied to the $35 coach weighing fee. In my opinion, this is the smartest $20 investment a motorhome owner can make. I am a strong supporter of this program and have been since I first heard of it in 1995. I have had each of our coaches weighed since then and will continue the practice for as long as I own a motorhome. RVSEF also presents an informational seminar at conventions and area rallies titled “RV Weight And Tire Safety.”
To help FMCA members to develop a better understanding of the weight and balance issue, I offer the following definitions of weight terms (along with some editorial comments). My primary source of information for this article is the “Recreation Vehicle Weight & Tire Safety Handbook,” which is provided by the RVSEF.
Gross vehicle weight rating (GVWR): The maximum allowable weight of the coach as it rolls down the highway. This figure includes fuel, water, LP gas, food, clothing, passengers, pets, etc. The GVWR data plate should be found near the driver’s seat in your coach.
When we weigh a motorhome, we need to compare the figure we get with the GVWR. We must think “worst-case scenario,” in that the coach’s GVWR is the heaviest the coach should ever weigh. We must consider that all tanks are filled. RVSEF figures indicate that water weighs 8.3 pounds per gallon; diesel, 6.8 pounds per gallon; gasoline, 5.6 pounds per gallon, and LP gas, 4.2 pounds per gallon.
You can obtain your coach’s gross vehicle weight by having it weighed on a platform scale, the type available at weigh stations, but the preferred method is to weigh your coach “at the four corners,” that is, at each individual wheel. This will give you much more specific information about how the weight is distributed.
Gross axle weight rating (GAWR): The maximum allowable weight for each axle. This information is located on the same data plate as the GVWR.
The GAWR assumes that the axle is loaded equally on both sides. This is why weighing your motorhome at each wheel, rather than at a platform scale, is so important. RVSEF’s “Recreation Vehicle Weight & Tire Safety Handbook” states that, “RVs are seldom loaded evenly from side to side, and, in fact, it is not unusual for us to weigh a unit that is more than 2,000 pounds heavier on one side than on the other.”
Since I spent my professional life in Marine aviation, I am acutely aware of the importance of proper weight and balance and its effect on the proper operation of components. We must give careful consideration to how we load the coach. We can come close to balancing the load from side to side, and front to rear. If the load is not balanced, it can adversely affect tire wear, steering, braking, suspension component wear, and more. Please do not take this issue lightly.
I load our coach with these thoughts in mind. My particular coach will be different from yours, but here is what I do: I place all smaller items in plastic storage containers and store what I use infrequently in the left-side storage compartments. Items I use frequently are kept in the right-side storage compartments (as viewed from the rear of the coach). I have found, through trial and error, that the load is balanced fairly well this way. When we were weighed at the Southeast Area Rally in Brooksville, Florida, I was pleased when I was told, “Don’t move a thing; the coach is as good as you can get it right now.”
Gross combination weight rating (GCWR): The maximum allowable weight of the coach (GVWR) combined with the maximum allowable weight of the towed vehicle. This also includes the towing equipment (and all the “stuff” packed inside the towed vehicle).
When you see a coach on the highway with a vehicle or a trailer in tow, do you ever wonder about the GCWR, and whether the coach’s braking system can safely stop both vehicles? We can hope that the towed vehicle has a supplemental braking system. This is another important concern addressed during the RV Weight and Tire Safety seminar.
The RVSEF says that 59 percent of the coaches it has weighed exceed one (or more) of these ratings. Don’t readily accept what the manufacturer lists as the coach weights; confirm that fact by weighing your coach for yourself. Bear in mind that the weight listed on the data plate does not incorporate the weight of dealer-added options — or the weight of your gear.
What should you do prior to having your coach weighed by the RVSEF at an FMCA convention or area rally? Plan to arrive with your coach loaded as it typically is when you travel. Don’t lighten the load to fall within specs and then reload when you return home.
We must develop a good working understanding of GVWR, GAWR, and GCWR so that we don’t put undue loads on a motorhome’s tires. They are where the “rubber meets the road.” Proper tire loading is a critical part of the coach weighing program. Correct tire pressure is based on the load on that wheel. Tire wear is a key reflection of proper — or improper — weight and balance of the coach.
If you ask how frequently people think tires should be rotated, the answer varies, from “never” to “every 10,000 to 15,000 miles.” The majority of responses seem to fall in the latter category, and this seems to be the best advice. Learn about specific tire wear patterns and know your tire manufacturer’s air pressure recommendations.
We should also be aware of the age of the coach’s tires. The manufacturer records the date the tire was made on the sidewall. Prior to January 2000, this information was listed as a three-digit number that followed the DOT information. The first two digits indicated the week of manufacture, and the third digit indicated the year. For example, 279 would be the 27th week of 1999. After January 2000, a fourth digit was added to clarify the year. For example, 2702 would be the 27th week of 2002. Don’t be too surprised if the manufacture date of a tire you are buying for your coach is several months previous. This isn’t always the case, but some tire shoppers have found that the tires they were considering buying for their coach were more than a year old.
If you’re buying new tires, check their manufacturing dates before they are mounted. According to various sources, including the RVSEF, a tire’s average life expectancy varies from five to seven years.
If your coach is parked outside in the sun all the time, ultraviolet rays will damage the sidewalls. It is a good idea to use tire covers in this case. Tires should be checked frequently for pressure, wear, damage, or cracks in the sidewalls. Don’t forget the inside sidewalls, also.
Take the time to be safe. Be sure to attend an “RV Weight And Tire Safety” seminar soon, and have your coach weighed once the seminar is over.
Happy trails to you and yours.