Looking at new wheels, don’t want to screw it up, so I could use some input with sizing. Thinking;
Wheel size/spec - Front 17x9.0, Rear 17x9.5. What is the proper offset for each that puts wheels at the edge, but no rubbing? And I know there is some personal preference that comes into play, I’m just looking for a “safe” range that helps move tire out.
Also, any suggestions on tire size(s), I think the rear would be a 275/45, but not certain?

 

On a stock body car? with or without fender work?

 

Stock body, without fender work

 

I am running 18x10 on all 4 corners so my backspacing/offset won't help you, but what I can offer is how i figured out how to get them to fit.

Clamp a spirit level (or any other very rigid and true piece of metal) to the hub face and use it as a reference to measure back to components like the springs, anti-sway bar end links, fender liner, etc. that are inboard of the wheel. That gives you the starting point for determining the backspace measurement. Then calculate how much the tire will stick out past the wheel at the widest point as well as the tallest point. You will also need to determine if the wheel will clear the brake caliper. You need to do all of this with the suspension loaded, i.e., with the jackstands under the shock center point. That will give you the final backspace measurement.

Then repeat for the outboard measurements to the fender. (I don't think "frontspace" is an official term, but it helps to think of it in that practical term.).

Overall wheel width = backspace + frontspace

1. Centerline = width / 2
2. Offset = backspace - centerline

NOTE: this is the physical overall width of the wheel but the advertised width is from bead seat to bead seat, so you will need to contact the wheel manufacturer with the overall wheel width and get their help in determining what their bead seat to bead seat measurement is to get the width

Repeat both for front and rear wheels.

 

thanks man, I’ll pull the wheel tonight and see how close I can get

 

https://www.rx7club.com/3rd-generati...input-1083660/

If you use MilesBfree’s method I’d add just a little “slack”. Tires can vary some in overall width even when both have the same stamped tread width.

 

Cool, thanks for sharing... Heck your post was most helpful. This is the basic set up, and the +48 is what I was concerned with/ curious about..

"FWIW, I have 255/40/17s on 17x 9 +48."

 

17" RPF1 setup for stock body no fender mods:

Front 17x9 +45 with a 255/40/17
Rear 17x9.5 +38 with a 255/40/17



You CAN do 275/40/17 on the rear but it MAY require fender rolling based on camber specs. 255 works great. I have the above specs

 

very nice, that gap and overall fitment is pretty close to perfect (in my mind).. Very well done and appreciate the feedback