Try this on for size?
 

Okay I'm really going to need to pull from the collective wisdom of the forum on this. I've got an 85.5 944 automatic that begs for a fourth gear on the interstate. Even on curvy secondary roads with 35-45mph speed limits I can just leave it in 2nd gear but still that is reving too high sometimes. I am seriously considering going from 215/60/15 on phone dials to 215/60/16. By my calculations that should take off close to 200 rpms which makes a difference and to me is worth the trouble. I have seen a few places selling 16" phone dials that are 7Jx16 with 52.3 offsets.
First of all, would these wheels fit my car as is or would I need spacers?
Would I need to make any adjustments to the car?
I'm not worried about throwing off the speedometer b/c it reads high already according to my Tom Tom. This combination should make it more accurate.
I would get the same size wheels and tires all around for simplicity sake and for rotation issues.
I did the same thing with one of my other cars, a 1977 Mercedes 450sel again with a 3 speed auto. I went from 205/70/14 to 215/70/15 and the results were terrific. It reved lower, even handled better, and the gas milage went from 15 to a whopping 16 mpg...
Thanks in advance to anyone who helps.
Dietrich

something to consider - going to a larger wheel to get taller effective gearing has a couple of drawbacks - weight and gearing change - the added weight will reduce acceleration - the taller effective gearing will too - if getting off the line is important, this may not make you happy

as to fitment, i'll defer to someone else on that, as i'm not sure where the break was

iirc the wheel offset changed in 87 so you'll need 1" spacers if you want to use those rims.

911 fuchs will bolt right on, and in my opinoin are the nicest looking wheel on a 944. there are also fake fuchs ,you can get a set of 7's&8's for under 600.00. I wonder if the turbo 16" wheels may fit as well??