I looked through quite a few posts and see that it is 6", but what is that in mm? I will either do 20 x 8.5 aftermarket or 17 x 8.5 vette wheels but need to know the best offset for the Blazer. I believe the front 17 x 8.5 vette wheels have a 45mm offset and the aftermarket 20s I am looking at shows 35mm offset. Thanks in advance.

Cajun

 

The two aren't interchangeable. 20mm is less than an inch. If you got 1" backspacing, you'd look like one of the lowriders with 13 inch 120 spoke gold wheels sticking out 5 inches past the fender. Offset is dependent on backspacing.

This is the most informative thread I've found to-date. Seems like offset is important more so for brake caliper clearance and if you want a 'deep dish' look.

EDIT: Whoops, forgot to link to the actual thread.

It really depends on your personal preference. As you can see from nj4x4blaze's post, his 20's have 35mm offset. The 18x8's I'm interested in have 20mm offset while another 18x8 had 40mm. I would venture a guess and say that the less offset the better because the mounting surface is closer to the center of the wheel. I'm not sure how little or how much backspacing would affect clearance issues (such as bigger brakes, etc.).

 

Yeah that makes sense. So what is the correct offset for a 4 x 4 blazer with 20 x 8.5 and 17 x 8.5 respectively? Thanks

Cajun

 

This tech article should answer all of your questions - Wheel Technical Information

The rim diameter means nothing when talking about backspacing and offset.

 

I just saw this thread. Ok for the 4x4 blazer the best offsets are +35mm and higher. The lower the number the more the wheel is going to stick out past the fenders and it's mostly in the front. The rear doesnt have this problem and trust me I know becasue I have 20's and they are +35mm. Mine stick out about 1/2" but that is also because I'm running a 20 x 9 wheel. So if you go with a 20 x 8 wheel you shouldnt have a problem. Now the real question is are you planning on lowering our truck or keeping it stock height? This is vital because you dont want a wheel that sticks out too much past the fender because if you bottom out it will hit the fender. If you plan on keeping it stock height I recommend getting a 255/45/20 tire because you will not have any rubbing issues. If you have any questions PM me or email me.

 

Good deal, I plan on going with a 20 x 8.5 with +35mm offset. Thanks for the info bro

Cajun