jlzhisname

*Sorry in advance for the long post*

I haven't been able to get a straight answer on this from anyone regarding this problem so I am bringing it here.

I have a set of 18x8.5 Cargraphic wheels that I am trying to calculate the correct offset. They are marked ET35 and I know for a fact they do NOT clear stock calipers like CG GMBh says. Some have told me ET 35 will clear stock calipers and some have said they will not. In any event I was given this link to help me figure it out and wanted to see if everyone agrees with the formula. After using it I come up with ET 19mm???

These are the measurements I recorded.



Measuring Wheel Offset

"To calculate offset you'll need the following measurements"

Wheel backspace
5.5" (139.7mm) to inner lip / 6.0ā€¯ (152.4mm) to inner EDGE

Wheel Width
8.5" (215.9mm)

Wheel Center line (outboard flange to inboard flange measurement / 2)
9.5/2 = 4.75ā€¯ (120.65mm)


Subtract:
Wheel center line from Wheel backspace to get offset.

139.7mm - 120.65mm = 19.05mm





Thanks in advance for the help!<ul><li><a href="http://www.rsracing.com/tech-wheel.html#backspace">http://www.rsracing.com/tech-wheel.html#backspace</a></li></ul>

MikekiM@PureMS

The shape and curvature of the spokes are the determining factor in brake clearance.
Lower offsets will help, but by no means are any indication of actual clearance or not.

Wheel offset is usually stamped on the inside of the wheel.

jlzhisname

OK. Thanks. I didn't know that. So what is the best way for me to figure out what spacers/bolts I need to get these wheels on the car?

MikekiM@PureMS

If you have the wheels, test fitting is the only way to see what size spacer you need.

Some aftermarket big brake manufacturers provide a template which allows you to test the wheels you have.