Tire size help...

I am in need of new tires on the rear of the 911. The front tires are still good with lots of tread left, but the car eats rear tires.

I am currently running the same size tires on staggered wheels. I have 16x6 wheels up front and 16x7 wheels in the back. I have 205x60x16 tires on both sets of wheels. In the future I'd like to remove a slight rubbing issue with the 205 tires, and eventually have a narrower tire front and rear. However since the current fronts are still good I want to move those to the rear and then put the new tires up front, and then when the rear eats this set, I'll have the narrow tires front and rear. (it makes perfect sense to me...)

My issue is changing to a narrower tire do I have to keep the same rolling diameter? Basically moving down from 205x60x16 which is 25" diameter tire to a 195x55x16 which is a 24" diameter tire.

So the question is: will there be an issue with a 24" diameter tire up front and a 25" tire in the rear?

These cars tolerate all kinds of crazy kinds of tire stagger, but I still think that this is a question that you should post on Pelican. I'm sure that someone there has tried this before.

octavious wrote: So the question is: will there be an issue with a 24" diameter tire up front and a 25" tire in the rear?

It will move the brake bias forward as the front will now effectively have more powerful brakes due to the change in leverage - much like putting bigger rotors on the front. You'll also drop the front by 0.5" meaning more forward rake. Correcting it with anything other than lift spindles will affect your front camber curve slightly. Other than that, in terms of diameter at least, there's nothing to worry about on a "dumb" car (without traction control/ABS etc where wheel speed inputs have to be considered).

I had no idea those cars ran such narrow tires. Guess I'm just used to looking at tires for 996s.

Bago-Yeah. Tiny tires. Some theorize that's why the tails would break loose in curves.

thatsnowinnebago wrote: I had no idea those cars ran such narrow tires. Guess I'm just used to looking at tires for 996s.

No kidding considering I'm looking at 205/45-16's for my little Fiat 500 right now!!

I'll second Pelican for a more complete answer. 99% sure that someone on there has done the same thing.

-Rob

Original size for my car was 185x70x15.

First of all beautiful little car. Whatever you do don't add carrerra rear flares. The narrow bodies will be more collectible in years to come. You didn't mention what brand of tires you're running and I assume you want to stay with same front and rear. That being said keep the 7 inch wheels on rear. With a 3.2 as opposed to original 2.7 I personally think you need to go to 225x55x16 on rear...may have to roll inner lips but keep in mind 3.2 weighs a good 150 to 200 lbs more depending on ancillariesthan the 2.7...especially mag case 2.7s.

Couldn't really tell for sure but you're likely running that car way too low. Maybe need to raise it An inch all around...as a 911 owner for 20 years trust me...it will handle sooooooo much better. Unless you're running raised spindles your likely having bump steer issues as well as not much shock travel.

If you do want to a square set up anything less than a quality 205x60 would be scary in a light weight 3.2 transplant.