Truck Tire Capacity

Check out TOYO. I don't know about 18's but some of their 17's tires (AT's for one) are about 400~500# better than more common rated tires.

gregchambers wrote:
Have ordered a 2015 GMC one ton CC SRW SB 4x4 truck. It comes with Michelin LT265/70R18E tires that are rated at 3525 lbs for a rear axle of 7050 lbs. Although I should be OK with stock tires, I wouldn't mind a little extra capacity cushion. In checking other tire manufacturers the only other size that I have found without going to extreme size jumps (which my stock rims probably wouldn't support anyway)or 19.5" is the LT275/70R18E rated at 7640 lbs for an extra 230 lbs of capacity. Does anyone know of another 18" tire that jumps up significantly in capacity without radically changing size and diameter?

Thanks!

do yourself a favor before you spend any money on a guess. Weigh the truck and TC Then figure out if its just tires or if it is 19.5s and tires.

While I totally agree with Buzz's advice and have given it myself regarding getting the rig weighed, the question then becomes: how much of a safety margin should a person go for? If the rear of the truck/camper weighs 6800 lbs and his current tires have a capacity of 7050 lbs technically the tire capacity exceeds the weight.... Personally, it's not enough for me.

I am just wondering what others think is enough of a safety margin?

I to would be interested in what others consider a reasonable safety margin. In doing research on tires I spoke with the manager of a well known nationwide chain tire store. Although he would be happy to sell me a new set of tires and also would give me a trade in allowance on my existing OEM's, he stated that LT tires are down rated because as truck tires the manufacturer knows that they will be worked hard and likely overloaded. He recommended that even at full capacity I would be fine. LT tires used on DRW setups are down rated slightly because there are times when only one tire carries the full or the majority of the load. Not sure I'm on board with his "go to the limit" theory but it is interesting.

I was within 5-10% of my rated tire capacity when towing with the TC loaded up and I had the WDH cranked harder to offload as much of the tongue weight from the rear as possible. With the 19.5" wheels, I no longer count everything I bring with me and use normal WDH settings. The wheels are heavier which required a shock upgrade from OEM, but handing was better with the 19.5's even with OEM shocks that had 85K miles on them.

I am of the opinion that GM does an excellent job of tire sizing. So if you stay within their published limitations for payload and towing capacity, you shouldn't have any issues with your tires - except, of course, for the usual problems of punctures, road debris, etc.

And how much "reserve" tire capacity? I think you'll find GM uses 15% and that seems to be a pretty common value throughout the motorized vehicle industry.

CapriRacer wrote:
I am of the opinion that GM does an excellent job of tire sizing. So if you stay within their published limitations for payload and towing capacity, you shouldn't have any issues with your tires - except, of course, for the usual problems of punctures, road debris, etc.

And how much "reserve" tire capacity? I think you'll find GM uses 15% and that seems to be a pretty common value throughout the motorized vehicle industry.

Barry...(nice job on your web site)-where does the 15% come from?

Thanx, Bill

15% is the difference between GVWR and (FAWR + RAWR) I would imagine.

On a 2006 2500HD, GVWR is 9200lbs. FAWR is 4500lbs. RAWR is 6080lbs.

FAWR + RAWR = 10580lbs.

115% of 9200 is exactly 10580lbs.

Toyo 285 75 18 MTs are rated for 4080lbs but they are 35" tires which would likely not fit the front of your Chevy without trimming even with a leveling kit.
Seems the closer to stock sizes are rated less, but look at Toyo And Nitto. They typically have the highest load ratings for light truck tires.
I have Toyo MTs on mine rated at 3970 and they handle my heavy @ss camper well with little to no sidewall flex.
Being mudders and since I had them siped as well they have not lasted very long. I got 20-25k mi on them now with about 5k hauling the camper and they are about 75% worn. I'm sure that would have been better if they weren't siped.

mkirsch wrote:
15% is the difference between GVWR and (FAWR + RAWR) I would imagine.

On a 2006 2500HD, GVWR is 9200lbs. FAWR is 4500lbs. RAWR is 6080lbs.

FAWR + RAWR = 10580lbs.

115% of 9200 is exactly 10580lbs.

Not on a diesel...

I think Barry was focused solely on the tire ratings.