now after doing some research the factory size for our wheel is a 17x8 with a +38 offset. if im wrong please correct me.
im currently running the stock BBS wheels with 15mm spacers.

i like the way the wheels are flush with the fenderwells.

now when i decide to go with another set of upgraded wheels, do i take the factory offset (38) and theN add 15? which is a +53 offset.

does that mean when i shop for wheels i need to select the rim size and ask it to be a +53 offset?

 

Other way around. Your +15mm spacers are pushing your wheels out, therefore decreasing your overall offset. By running a +15mm spacer on a +38 wheel, your new offset is effectively +23, not +53.

Another thing to consider is the wheel width itself. A 17x8 +38 wheel such as yours will not have the same "flushness" as a 17x9 +38 wheel. This is due to the fact that you now have a wheel that is 1" wider then the original and will therefore stick out more.

The last thing to consider is your inside wheel clearance. When you increase the wheels width to say a 17x9 such as above, the wheel will not stick out 1" further. In fact, it will stick out 1/2" on the outside, and 1/2" on the inside, towards the strut/coilover/suspension components.

 

no, you would subtract. pretty much the lower the offset, the further the wheel will stick out.

and you are right about the stock wheels

 

thanx for the info. I always wonder about offsets and stuff never got the time to really look into it.

 

Can you please post some pics i want to do the same to my car 15mm