Originally Posted by Jamesr6967

The deeper offset was to allow room for the ABS system hardware on the late 944 models.

Originally Posted by FrenchToast

You'll notice on your friend's car they don't sit further in the fender, but sit the same way the proper wheels for your car do.

The offset was changed to allow for ABS-ready hubs for '87 and newer cars. Mind that not all '87+ cars came with ABS, however. Edit: Jamesr6967 beat me to it!

The difference can be easily seen by peeking inside the rear wheels on both you and your friend's cars, and looking at the depth of the brake hats.

Take care!