What is the backspacing on the factory 15 by 7s and the factory 16 by 8s?

Thanks in advance

the factory backspacing for the 15x7 is 4.5 inches and I'm pretty sure (99%) that it's the same on 16x8's also...

Ok that has to be a record speed for a reply, I didnt expect one for a few hours. Thanks for getting me the info so fast.

In case it matters, the stock offset on the 16x8's is +0mm front and +16mm rear. Not sure on the 15x7's.

aren't the front and rears different?

what about T/A 20 slots? any info on Back Spacing?