Ordering snow tires...need help with sizes
 

I am going to order some Blizzacks. The skinnier the tire the better so I plan on ordering 195/65-15.

Page 98 of my Carrera owners manual indicates for the front rim 6j x 5 or 7j x 15. The rear rim is one size larger (7j x 15 or 8j x 15 respectively).

I am a newbie at this so bear with me. For 911's are the rear rims always one inch larger in width?

For most 911's the rears are 1" larger. The most common pre-'89 sizes for rims are/were (the early cars weren't always two sizes, but I'm not sure when that changed, late 60's or early 70's)

15x6 f & 15x7 r
15x7 f & 15x8 r optional wheels
16x6 f & 16x7 r optional wheels

In '89 the standard car came with 16x6 and 16x8

Turbo's in certain years came with 16x7 and 16x9

PS If you take your wheels off most of the wheels that came on 911's had marks on the back side that had size indications.

I think you would be looking for something like 6j or 7j as the width.