[Mike Tucker]

Good afternoon. I just bought the 2021 GMC Sierra AT4. It came with the LT275 65R18 wheels and tires. It comes with a factory 2” lift.

What I want to do is to see how big I can go on a 18” rim and a 20” rim without rubbing or doing any trimming. I can not do a leveling kit for it would void the drive train warranty per GMC.

I spoke to someone and they said the biggest I could go would without rubbing or doing any training.
18” - 285 70R 18 or 33.7 x11.2
20” - 285 60R 20 or 33.5 x 11.2

if I am able to do this what would be the best for it. I would like to come out past the wheel well about an inch but the gentleman said it would rub reguardless. I am also not sure of the offset as well. To give it the look of coming just past the fender well. This is primarily for astatic look.
18x9 or 18x10
20x9 or 20x10
Looking for opinions and help. Any feedback would be greatly appreciated

Thanks
Mike

 

[srvonallmen]

Hi Mike,

Recently put new wheels and tires on my 2020 Silverado 1500 LT. 20x9 0 offset with P275/60R20 Falken wildpeak AT3W. I have a 1.5” level in the front and am going to put 1” in the back just haven’t gotten to it yet. My tires do not rub at all with no trimming but it’s close at full lock. The outer edge of the tread is just outside the fenders so the tire sidewall is outside by about an inch. You’ll have an extra 1/2” of lift so I’m sure you’ll fit that same setup if that’s what ur looking for. Also apparently I can only add one photo at a time but I’ll get them up so you can see them. Hope this helps.

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[srvonallmen]

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[srvonallmen]

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[Daly]

295/70r18 seems to be the biggest tire that has given the least amount of trouble on the AT4 and Trail Boss trucks. Some have even got 35's to work, but I think it depends on tire manufacturer. Also this is with a stock offset wheel.

For wider wheels with less offset (stick out more), you'll be able to get away with a wider tire, but it'll be a shorter tire.

I hate giving them business, but Custom Offsets does have a pretty good gallery of customers vehicles and thier set ups. I'd have a look in there and see what works.