High capacity 20" tires for truck

[Second_Chance]

I posted this on the Silverado/Sierra forum and got one response... "good luck." Since folks on this forum are more into towing than jacking trucks up to make them look macho, I'll see if anyone here knows of anything:

My wife and I are full-time RVers. Our truck is a 2013 Sierra 2500HD SLT CC D/A with the 20" wheel option. While the 20" alloy wheels look very nice, I'm having trouble finding a higher capacity tire than the stock LT265/60R20 load range Es that came on the truck. I'm looking for input on either: 1) load range F tires in the LT265/60R20 size, or 2) suggestions for replacement wheels in a size where load range F tires would be available without changing the outside diameter of the tire/wheel combo (currently 32.5"). I'm happy with the current gear ratio and the performance of the D/A when pulling our house-on-wheels. I could tolerate a slightly smaller diameter, but not anything larger (wouldn't mind a few more RPMs at cruise where the tranny would shift into 6th a little sooner).

The pin weight on our fiver as currently loaded is right at 3,000# which puts us just barely under the rear axle rating (GAWRR) for the truck when pulled across the scales (verified both on CAT scales and a wheel-by-wheel weight system proprietary to one of our RV clubs). The total capacity of the tires is a few hundred pounds above the axle rating, but I'd still like to increase that safety margin. I understand that no aftermarket modification (tires, air bags, etc.) can/will increase the ratings of the truck... it is what it is. I'm just looking to increase the safety margin on the most likely thing to fail.

[Grit_dog]

therink wrote:
That is the reason SRW 1 ton trucks don't have the 20" wheel option available. I recommend going with 18" wheels and load rage E tires. The stock Michelin 265/70R18's on my one ton are rated for 3525 lbs.
I'm sure you know but no matter what you do with tires, it will not increase the load carrying capacity of the truck. That is a lot of weight for a 3/4 ton.

Fords and Rams do. And I've driven my big fat pudgy camper all over the place with new ram OE 20" takeoffs. I've read they're rated for 3600lbs but OE rim ratings are kinda hard to find IMO. However one can be certain that whatever leaves the factory in a particular configuration is rated up to the rawr. So if you can get a certain combo on a 3500 gasser with the "best" payload, that will apply to the diesel which is the same save for more weight over the front axle. (and a little more on the rear axle for the numbers crunching weight cops)
Cheap option for op to upgrade tires is buy a set of Firestone Ram Transforce takeoffs. Can be had for like $500 every day in CL. A lot of people dump them for better/more aggressive tires.
Or if 18" rimz are your huckleberry, seen a lot of GM takeoffs for sale.
For close to zero$ you could buy another set of takeoffs in a flavor that make you feel better and sell yours.

[calsdad]

Excellent thread.

Does anybody know where to retrieve the weight ratings for the different GM factory rims?

I just upgraded my 2003 Chevy Suburban 2500 to a 2010 Yukon XL 2500 and I'm similarly interested in upping the capacities of the truck to both increase the towing ability and safety margins if at all possible.

The truck is going to need tires within a year or so, I'd like to upgrade the tire capacity if possible - and if I have to go to 18" rims I'd do that.

It currently has the 17's that look like this:

[gmcsmoke]

I would jump down to a GM 18", the rims are the likely weak point in the mix. My 18" are rated for 3900 a piece. I'd also add a helper spring, I think you'll want the added stability with a 3k load in the bed.

[Second_Chance]

gmcsmoke wrote:
according to michelin the tires are not the limiting factor (3,195 each). what's the unloaded rear axle weight?

The tires on the truck are not Michelin, but they're rated at 3,195# each. The scale weight on the rear axle (with occupants, full fuel, tonneau cover that stays folded up while towing, and Andersen hitch) is 3,080. With a GVWRR of 6,200 that leaves 3,120# for payload on the rear axle and 3,310 for payload on the tires. Last weigh-in (Escapees SmartWeigh), the pin weight on the trailer calculated at 2,925 - although one side of the rear axle on the truck weighed a bit more than the other. I'm within specs and maybe just worrying too much...

Rob

[gmcsmoke]

according to michelin the tires are not the limiting factor (3,195 each). what's the unloaded rear axle weight?

[Bedlam]

Going to commercial 19.5's gives you much stiffer sidewalls for better weight carrying and handling at load. They are overall thicker tires which resist puncture and road hazards more than the LT's. Tread wear is better with the 19.5's than LT's and most can be regrooved.

Down side to the commercial tires is poor flotation on sand, a harsher empty ride, the heavier tire may require heavier dampened shocks, and slightly lower city mileage due to the weight.

[fly-boy]

Not sure you earn much in the way of additional safety by getting new rims and higher capacity tires. Very little bang for the buck in my opinion.
If you are below your tires capacity you are below it. So getting higher capacity tires provides you little in the way of safety. Road hazards are road hazards regardless of tire capacity...
If you really want piece of mind you could get a dually but you can also have issues there too.
I suggest you simply buy quality tires, follow tire mfg. recomendations, and drive carefully.

[Me_Again]

I believe the OEM RAM 18" and 20" tires have the same 3638-40 rating, however I have heard the wheels are only rated to 3500. Chris

[jus2shy]

therink wrote:
That is the reason SRW 1 ton trucks don't have the 20" wheel option available. I recommend going with 18" wheels and load rage E tires. The stock Michelin 265/70R18's on my one ton are rated for 3525 lbs.
I'm sure you know but no matter what you do with tires, it will not increase the load carrying capacity of the truck. That is a lot of weight for a 3/4 ton.

Just to ensure there isn't additional confusion with this comment, I hope you're just commenting on GM specifically. I personally don't know GM's weight ratings for GM's 20" rims. However for RAM and Ford, they both use 20" rim based tires I noted in my recommendation for 1-ton SRW vehicles. Feel free to check out their respective vehicle configuration tools.

[Second_Chance]

Thanks, everyone (and Steve - I do realize that nothing will change the gross or rear axle ratings). And thanks, Bedlam - I'd been thinking about 19.5s because of the availability of tires widely used in commercial applications and on MDTs.

To everyone... you've been SO much more helpful than the lone responder on the truck forum!

[Bedlam]

245/70R19.5 are about 33" tall You can get the rims in 4500 lb (Vision) or 5000 lb (Rickson) capacities. The tires are load range G or H and wear much better than typical LT tires.

These are Vision rims with 245's on my Ford:



The AAM axle in your GM is rated for over 10K lbs and the downgraded rating for your truck is due to the selection of suspension and wheels by GM.

[therink]

That is the reason SRW 1 ton trucks don't have the 20" wheel option available. I recommend going with 18" wheels and load rage E tires. The stock Michelin 265/70R18's on my one ton are rated for 3525 lbs.
I'm sure you know but no matter what you do with tires, it will not increase the load carrying capacity of the truck. That is a lot of weight for a 3/4 ton.

[Dhende3665]

The new trucks with 20" tires have 3750 capacity now

[StirCrazy]

adding to way2roll 3750 is just the rating of one brand of tire, my 2014 f350 came with tires rated for 4078lbs, it all depends on the size of tire.