Weight Sticker Math Exercise

Vic R wrote:
Hi all – I’m trying to make sense of all of the weight data that I have:
1 – Cat Scale Weight w/ Camper on – 10920
2 - Cargo Weight Rating Sheet – 2802
3 - GVWR (door sticker) - 11700
4 - Tire and loading (door sticker) occupants and cargo should not exceed 3668


********** I did actually get the weight by axle. It was (f)4920/ (r)6000 and my door sticker said not to exceed 6000/7000, so I'm good there

Vic R - You cannot determine the curb weight of your truck from the information you have. Also, you cannot determine the camper weight either. Although they are related to some degree, there is no direct relationship between GVWR, axle weights and rated payload.

The only way to get these weights is to weigh your truck with the camper off and then compare that to your weights above.

I always find that there is a lot of misunderstanding and misinformation around weights and ratings

Front Axle - Your GAWR(front) is 6000 and your actual is 4920 so you are well under. IMO it is not a good idea to exceed GAWR.

Rear Axle - Your GAWR(rear) is 7000 and your actual is 6000 so you are well under here too. You can safely add 1000 lbs of gear.

COG - This was mentioned as being important which is true. In your case however, I would say that your COG is well within limits because if you look at the GAWRs, the ration of front to total is 46%. Your actual ratio is 45% which is good. If the COG is too far back, it will take weight off the front axle and put it on the rear. This can affect the handling and braking ability. This is where the payload rating comes in. If you overload the rear, it will change this ratio. Again though, you are just fine.

Tire Rating - Your tires are rated at 3668 which doubled is 7336 per axle. You are good on both the front and rear. Tires are another rating that you should never exceed. Also, the age of your tires is important as someone already mentioned. As tire age, they are prone to delamination and cracking. However, this to some degree is factored into the rating.

GVWR - Your rating is 11700 and your actual is 10920. You are well under your GVWR and have 780 lbs of additional capacity. However, unlike axle or tire ratings, there is a lot of "fat" in the GVWR ratings as it covers so many different components (transmission, brakes, driveline components, cooling, etc. etc.) In my opinion and that of many others, it is acceptable to exceed the GVWR by some margin. My limit is 10%, but others have exceeded it successfully by much larger margins. This is something you need to decide for yourself and it depends a lot on where and under what conditions you will be driving. For example, if you are driving a lot of steep mountain roads in hot weather, you may want to stick to the GVWR, but if you are mainly on regular highways in normal temperatures, then going over is acceptable IMO.

The suggestion that you should stay below 80% of GVWR has no valid engineering basis. Might be a reasonable suggestion as it would definitely extend the lifespan of your truck to some degree, but as also mentioned, given the wieghts of TCs and the capacity of trucks that most of us can afford, this is just not practical and definitely not necessary.

You cannot subtract the weight of your wheels and tires from the ratings. This is often asked, but this is already taken into account when they set the ratings.

So the bottom line here is that you have a really great rig that you can be totally confident in driving down the road. You have some surplus capacity to carry more stuff without having to worry about it. And no, you are not over thinking this. Safety of yourself, your family and the rest of us on the road is important so it is great that you are asking the questions and trying to educate yourself so you can make the right decisions. Now go out and enjoy your rig!! :B