Q. We have a 30-foot Forest River Sierra fifth-wheel. The manufacturer’s weight sticker lists the gross vehicle weight rating (gvwr) as 11,385 pounds. The maximum rated load on the tires is 2,640 pounds per tire, for a total of 10,560 pounds. That is 825 pounds less than the gvwr. Which figure do I use to determine if I am overloaded, and why would there be such a difference? I would think being more than 800 pounds overloaded would be quite a hazard.
— R.C., Cave Creek, Arizona
A. I’m really glad people are reading and paying attention to weight and loading; we’ve been harping about it for years. Fortunately, you are overlooking the hitch weight, which should be at least 15 percent of the total trailer weight on a fifth-wheel unit. At the gross weight of 11,385 pounds, that hitch weight on a properly balanced and fully loaded trailer would amount to at least 1,708 pounds.
You should park just the wheels of the fully loaded trailer on a scale to be sure it’s within the 10,560 limit. Then park the unhitched trailer on the scale (landing gear down) and weigh it again. It should now weigh no more than 11,385 pounds (gvwr). The difference between the weight on the wheels and total weight (unhitched, parked on scale) will be the hitch weight.
Ken Freund’s more than three decades of auto-repair experience and 20-plus years of RVing helped him author numerous books and articles on vehicle repair. In addition to RV Clinic and Performance, he writes the Powertrain column in MotorHome magazine. Ken has been a California Automotive VO-Tech and Smog-Test Program Instructor and an ASE-certified Master Automobile Technician.