Biggest Tire On Stock 20" Wheels

07Sierra4x4 · September 19, 2009

Heys guys I'm new here and just have a quick questions about tires. I know there are several previous topics about this but I can't seem to answer the question I'm looking for. I have a 2007 GMC Sierra Extended Cab 4x4. I currently have 275/55/20 stock tires and I'm basically wanting to know what the biggest tire I can run without any rubbing and without a leveling kit. I have been looking at 275/60/20 and 285/55/20. Will either one of these work. I know the 275/60/20 it about 32.9" tall but it is also no as wide as my current tires so I'm thinking they should fit?

74fencer · October 4, 2009

I am curious also

Matt_ · October 4, 2009

Heys guys I'm new here and just have a quick questions about tires. I know there are several previous topics about this but I can't seem to answer the question I'm looking for. I have a 2007 GMC Sierra Extended Cab 4x4. I currently have 275/55/20 stock tires and I'm basically wanting to know what the biggest tire I can run without any rubbing and without a leveling kit. I have been looking at 275/60/20 and 285/55/20. Will either one of these work. I know the 275/60/20 it about 32.9" tall but it is also no as wide as my current tires so I'm thinking they should fit?

The first number of the size is the width. So the 275/60/20s are the same width as your stock 275/55/20 tires. They're both 275mm wide.

09Jimmy · October 4, 2009

285/55R20s will rub on the rear of the inner fender when you have the wheels turned and are in reverse. My BFG All Terrains did.

jonathansnyder · October 4, 2009

Do not get 275/60/20 if you don't want it to rub. I bought a set of tires online and that's what I bought. Now don't get me wrong, I love them, and they look fantastic on the truck, but I had to get a leveling kit in order for them to fit. Seriously, I couldn't turn the wheel in either direction more than like 3/4 of a turn.

It looks sweet though:

Edited: Found a better pic...

Matt_ · October 4, 2009

^^^whats the width and backspace on those wheels???

jonathansnyder · October 4, 2009

No idea. Why do you ask?

Matt_ · October 4, 2009

Because fitting a tire on these trucks is greatly dependent on the wheel width and backspace. From your pics, i'd guess that those wheels are 9" wide and 5 or 5.5" backspace.... which would likely result in rubbing issues even with an almost stock sized tire.

jonathansnyder · October 4, 2009

Because fitting a tire on these trucks is greatly dependent on the wheel width and backspace. From your pics, i'd guess that those wheels are 9" wide and 5 or 5.5" backspace.... which would likely result in rubbing issues even with an almost stock sized tire.

Well, I will tell you that before I had these tires, I had a set of 285/50/20's on these same rims and only had the issue 09Jimmy spoke of earlier.

Matt_ · October 5, 2009

275/55/20 = 32.1x10.8

285/50/20 = 31.4x11.2

275/60/20 = 33.2x10.8

The 285s are quite a bit shorter than stock, and just a tad wider.... they should fit on stock wheels without any rubbing issues. You had rubbing issues because of your wheel width and backspace. If you rubbed with those 285s, its not a surprise you needed a leveling kit for the 275/60/20s because they're almost 2" taller.

Changing wheels on these trucks makes fitting tires a nightmare

Edit was 09jimmy running stock wheels? I don't see 285/50/20s having any fitment issues otherwise...

jonathansnyder · October 5, 2009

You had rubbing issues because of your wheel width and backspace. If you rubbed with those 285s, its not a surprise you needed a leveling kit for the 275/60/20s because they're almost 2" taller.

Changing wheels on these trucks makes fitting tires a nightmare

I'm not doubting you, just posting my experiences.

Also, buying wheels on craigslist from some guy in a garage doesn't help either

Matt_ · October 5, 2009

You had rubbing issues because of your wheel width and backspace. If you rubbed with those 285s, its not a surprise you needed a leveling kit for the 275/60/20s because they're almost 2" taller.

Changing wheels on these trucks makes fitting tires a nightmare

I'm not doubting you, just posting my experiences.

Also, buying wheels on craigslist from some guy in a garage doesn't help either

lol i know man. just trying to help.... tire sizes are confusing enough on their own (for instance how the 285 is actually a smaller diameter than the 275), add in the square wheel wells that our trucks have and now we're stuck with wheel width and backspace playing a huge role in what fits.

You do have a sweet looking truck there too... thats my favorite color by far