max wheel backspacing

[dsm144]

Hey guys im trying to decide on a set of wheels for my car. I want to go as wide as possible and i know the sweet spot is supposed to be +40mm offset but i havent found anything that accounts for wheel width. Does anyone know the max backspacing i can get away with? I want the wheel as close to the suspension as possible with no rubbing. Also im looking at either 18x8.5 or 18x8.75 with a 225/40 for now.

 

[2slow4now]

There is a bunch of threads on wheel/tire size. There are alot of variables car to car.
Best thing to do is measure. Use a tire calculator to help figure out the math and you can measure on your car. Custom rims, wheel tire packages for your ride - RIMSnTIRES.com

I don't know if it carried over your specs but comparing a 205/55r16 x6.5 +46(stock size) and a 225/40r18 x8.5 +40 shows the diameter almost the same. 4mm closer to your suspension on the inside which you can measure. The big problem is it would stick out 16mm towards the fender lip.

If you don't have stock size on right now you can still plug your tire/wheel specs in and physically measure for clearance.