2011 GMC ALL-TERRAIN..... 20" rims, what size of tire can i go??

[D-MOE]

Hey guys,... and gals

 

I have a 2011 GMC All terrain with stock 18's.... looking to step up to 20's just to save my rotors and calipers since i do alot of off-roading for work. My truck has a leveling kit and air bags..... Every tire shop i talk to gives me a different story... 305/60's will fit (with no rubbing) or 285/55's is the max..... thought id join up and see what people have found worked best for them????

Thanks

Donny

[Big Whiskey]

I'm not sure how switching to 20's will save your rotors and calipers....but anyway....if you stay with a factory offset/backspacing, you can run a 285/55/20, 275/60/20, or 305/50/20 easily with a level kit. A 295/55/20 or 305/55/20 will fit with a little trimming. The 295 might even clear without trimming. A 305/60/18 will fit, but there's no way in heck that a 305/60/20 will work.

[D-MOE]

thanks for the info..... my reasoning with the calipers and rotors is that the mud builds up between the rim and caliper. the rocks scrape at them as well as the rim. theres been a couple guys who i work with that had there rims seperate from this issue. And they have found that there brakes have lasted alot longer. I know it sounds strange:)

 

What is the factory offset? 0? I wish i could see a few pics of what each size would look like.

 

If i dont stay with the factory off set could i go with a +5 or +10 and fit the 305/55's?

[Big Whiskey]

Factory offset is +31mm for the factory chevy 17, 18, and 20 inch rims. The backspacing will vary accordingly, because the 17's are 7.5" wide, the 18's are 8" wide, and the 20's are 8.5" wide. So, keeping to a more positive offset, like +30, +25, or +18 (those three seem to be the most common) will keep the rims tucked under the fenders more...which will also reduce the chances of rubbing. Running a 0 offset will probably require trimming with any of the sizes mentioned. A 9" wide rim with +18mm offset seems to work very well.

[sab316]

I have stock 20's with 295/55/20 (33x12.5) and I rub sway bar at full lock.

[D-MOE]

didnt have to do any modifying?

[sab316]

Nope, never rubbed plastic or trimmed anything.

[D-MOE]

Nope, never rubbed plastic or trimmed anything.

 

 

Are your tires even with the fender or do they stick out a bit?

[becker87]

Just for reference, here is a picture of my truck with the stock GM 20s with the stock 275/55/20s. I will be switching to 275/60/20s before winter. It's not the best picture of tires, but you get the idea.

[blackout07]

Op from the sounds of it, you don't want anything bigger than 285/55. Any of those larger sizes will rub the fenders when your off road, unless you dont mind trimming. That will fix fender rubbing but theres nothing you can do about the rubbing on the sway bar though other than aftermarket wheels or wheel spacers. I wouldn't be comfortable having my tires rub on the sway bar.

[lilnasty]

My factory goodyears rubbed the sway bar after I installed my leveling kit. Didn't notice when dry but when it rained I would always hear a squealing when turning into parking lots. When I rotated my tires, I noticed the sway bar's paint was rubbed off. Had a friend cut the wheel while i looked underneath and sure enough. Now with my Duratrac's I can feel the tire inside lug rub when at full lock.

[kstruckcountry]

Anybody who does any really serious offroading goes no bigger than 17's.

 

I've never had any issues with mud buildup. You're more likely to destroy a rim by having 20's and busting a rim on something.

[D-MOE]

Op from the sounds of it, you don't want anything bigger than 285/55. Any of those larger sizes will rub the fenders when your off road, unless you dont mind trimming. That will fix fender rubbing but theres nothing you can do about the rubbing on the sway bar though other than aftermarket wheels or wheel spacers. I wouldn't be comfortable having my tires rub on the sway bar.

 

 

How'd you guess? You operating as well? ..... Just ordered KMC XD rock stars in matte black.... 20x8.5 with a +10 offset..... I know they're Getting old cause everyone has them but I wanted a lower maintenance rim...... I ordered 305/55/20's but I'm starting to regret it after seeing more posts! I called Truxxx to see what they recommended and he said with little trimming this size would look best...... I ordered them yesterday from discount tire direct, wonder if I could change my order

[D-MOE]

Anybody who does any really serious offroading goes no bigger than 17's.

 

I've never had any issues with mud buildup. You're more likely to destroy a rim by having 20's and busting a rim on something.

 

 

All Im doing for offroading is driving to work, it's gumbo and the rims get caked.....

[bigb9298]

I just put some Nitto terra grapplers on my 2011 gmc cc truck

And they run on the inter wheel well push tab. 275/65/20