Originally Posted by MaryNJWildlife
Front curb weight
Rear curb weight
Total curb weight
= 3980 (after reading, I learned that this includes fuel)
Max payload = 1195
GVWR = 5311 (not sure why this is not equal to the curbweight + payload)
Maximum tow capacity = 3500
GCWR (by my calculation) = 3980+1195+3500 = 8675
I doubt that your GCWR is the total of the curb weight plus the payload plus the maximum trailer weight. It doesn't work that way. It's probably less than that, maybe quite a bit less. For one thing, part of the trailer weight (typically around 10-15%) is carried on the hitch and reduces available payload. For another, tow ratings assume two people and minimal additional payload; more than that in people or equivalent cargo reduces the maximum trailer weight.
There are four primary weight ratings supplied by the vehicle manufacturer:
GVWR: maximum recommended weight of the vehicle and everything in it, including any trailer weight carried on the hitch (tongue weight)
GAWR (front and rear): maximum recommended weight carried by each axle
; the rear axle
is the one to watch
GCWR: maximum recommended total weight of vehicle, trailer, and everything in both
Payload, tow rating, and tongue weight rating are derived from the above ratings, and there is give and take among them.
The trailer also has a GVWR and a GAWR.
In addition, tires
have weight ratings. Generally the combined rating of both tires
on an axle
is more than the GAWR to allow for a little left-right imbalance. However severe left-right imbalance can overload a tire on one side without overloading the whole axle.
To find out if WDH is indicated, you should load the trailer and vehicle (people and cargo) as you normally do and weigh each axle. If the vehicle's rear axle approaches or exceeds the GAWR, adding WDH will transfer weight from the vehicle's rear axle to the vehicle's front axle AND to the trailer's axle.
And as if that isn't enough to give us all a headache, there is frontal area to consider. Tow ratings are tested with low profile box trailers. The added height and width of a typical travel trailer puts additional strain on the drivetrain at highway speeds or when towing into a headwind, partly mitigated by the rounded shape of many molded trailers. Some manufacturers address the frontal area issue by slapping on a limit; many ignore it. But it's a good reason to stay well within the GCWR of your vehicle.