Difference Between Trailer Hitch Rating and Rating When Used with Weight Distribution System
Question:
Hi. Im new to towing, trying to understand how some of the physics work. From my parts days, Im used to seeing hitches that have a weight rating thats 20 higher when used with weight distribution. But the other day, I saw a 2006 GMC Envoy with a weight carrying rating of 400lbs and a weight distribution rating of 900lbs, more than double. Does this have anything to do with the shorter wheelbase? Is it because of the softer suspension? Ive looked all over the internet, and I cant find anyone talking about this. It seems like a lot of trucks dont even have a dedicated tongue weight rating.
asked by: Zach K
Expert Reply:
As you mentioned in your question many trailer hitches will have a higher weight rating when used with a weight distribution system. This is simply because a weight distribution system will distribute some of the tongue weight to the front axle of the vehicle, taking that load off the rear axle and thus allowing the hitch to handle more trailer weight.
The difference between a hitch's rating and its weight distribution rating is typically only specific to the hitch itself and not necessarily the vehicle it's installed on. This is what the hitch manufacturer has determined through testing that the hitch can safely handle in either application.
I did also take a look at the online owner's manual for the 2006 GMC Envoy and I'm really not sure why it lists such a large gap between the two ratings (400 without WD and 900 with WD as you mentioned). It could certainly be the wheelbase or suspension on this particular vehicle but it could just as easily be the rating on its factory trailer hitch that was determined by the hitch manufacturer. I wish I knew for certain the specific cause for the weight ratings gap but there are just so many components both on a vehicle and the hitch that could affect it that it's really difficult to pinpoint. It is simply what the manufacturers have detrmined through testing to be the hitch and vehicle's safe limits.
