a friend says he put 245/45/17 on the rear of his 2nd gen and 225's in the front

does that mean 205/40/17 will most definitely fit on my 2nd gen??

 

Yes they will. Just make sure the offset is correct.

 

that reminds me
the owner doesn't know the offset.

is it easy to measure the offset by hand? or is it a specification thing...

 

The correct offset varies depending on vehicle and rim combinations.

 

what o_O? i know for sure that my 2nd gen is 40mm

the rims i am looking for have unknown offset values. is it possible to manually measure the offset on the wheels? sorry for the vagueness.

 

Really? I have never seen a rim that dosen't have the offset engraved/molded into the back side of the rim. I believe with a 17x7 rim you would want a 38-40 offset on a FC.

Only other thing I could think of is test fitting them on your car. I don't think there is an accurate way to measure the offset without special equipment.