AudiWorld Forums - Wheel whore tech: Wheel fitiment 101

I like to the flush to the fender look for all my Summer wheel setups. So here is a guide for those of you who want to achieve the same look.

With my first set of 19" wheels that a 19x8.5 ET33 front and 19x9.5 ET33 rear was the best combination after doing some alignment tweaks in the rear to fit the tire behind the lip.

So using a 8.5" wide wheel with ET33 offset as the goal lets go do some math and I'll show you some tricks only a wheel whore would know.

First of all wheel dimensions are retarded for the following two reasons:

- Width of a wheel is given in inches
- Offset of a wheel is given in millimeters

My current set of Rays wheels are 18x8 ET31 front and 18x9 ET35 rear

Front setup:

So when you compare an 8" wheel to an 8.5" wheel there is 0.5" of difference in width.

0.5" = 12mm so you split that in half and you get 6mm.

If you used a 6mm spacer in conjunction with a 8" wheel the face of that wheel should be exactly the same distance from the hub as the face on the 8.5" wheel.

So we have a 6mm spacer in mind but we want to get to an offset of ET33. Since the front is ET31, which is LOWER than our ET33 reference, we SUBTRACT 2mm from the spacer we have in mind.

So 6mm - 2mm = 4mm spacer.

Rear setup:

So when you compare an 9" wheel to an 9.5" wheel there is 0.5" of difference in width.

0.5" = 12mm so you split that in half and you get 6mm.

If you used a 6mm spacer in conjunction with a 9" wheel the face of that wheel should be exactly the same distance from the hub as the face on the 9.5" wheel.

So we have a 6mm spacer in mind but we want to get to an offset of ET33. Since the front is ET35, which is HIGHER than our ET33 reference, we ADD 2mm to the spacer we have in mind.

So 6mm + 2mm = 8mm spacer.

Now lets go test this all out...

If you are a true wheel whore you might happen to have a set of 2mm and 3mm spacers in your possession.

Why 2mm and 3mm specifically? Well with those two sets of spacers you can create ANY width from 2mm to 10mm using any combination of 1,2,3 or all 4 of them.

Once you figure out the exact spacer you want for the front and rear wheels you would then go buy them in that size or have them made.

This is a pair of 2mm hubcentric spacers I had made for me

<img src="http://podi.ca/winstontemp/rayswheels/IMG_3112.JPG">
<img src="http://podi.ca/winstontemp/rayswheels/IMG_3113.JPG">

This is a pair of universal 3mm spacers

<img src="http://podi.ca/winstontemp/rayswheels/IMG_3114.JPG">
<img src="http://podi.ca/winstontemp/rayswheels/IMG_3115.JPG">

So jack the car up

<img src="http://podi.ca/winstontemp/rayswheels/IMG_3116.JPG">

Remove the wheel and I used both 2mm spacers to make a 4mm one

<img src="http://podi.ca/winstontemp/rayswheels/IMG_3117.JPG">

Put the wheel on and hope that is clears your brake caliper. You will know if it doesn't since the wheel won't be flush with the hub.

<img src="http://podi.ca/winstontemp/rayswheels/IMG_3120.JPG">

Spin the wheel to make sure the wheel doesn't touch anything. I have a nice 2mm gap between the wheel and the brake caliper so SUCCESS!!

<img src="http://podi.ca/winstontemp/rayswheels/IMG_3118.JPG">
<img src="http://podi.ca/winstontemp/rayswheels/IMG_3119.JPG">

The rear setup is a lot easier to deal with since you don't have to worry about brake caliper clearance.