305/25-20 and 245/30-20 on a 997 TT?
 

Anybody running 991 TT sizes on their 997 TT? Also, I was looking at stock
997 TT sizes and noticed quite the difference between front and rear diameter,
wasn't this an issue on the 996TT? Anybody know the tolerance?

I believe the common move is to run 325's on the rear to get the diameter ratio right with 20's.

What I meant was, 245/35ZR20 in the front and 305/30ZR20 rear.

You can't run those. They are way too big.

What RyeM3 said - do some research and plug your sizes in here:
http://1010tires.com/Tools/Tire-Size-Calculator

Talked to Damon at Tire Rack today, he recommended;

245/30-20 front 25.8 dia
325/25-20 rear 26.4 dia

In a PSS. He said the 996 TT ran same dia front and rear while the 997 TT
runs a slightly larger rear, checks when you do the math on the stock sizes.

Have you considered that the 997 was designed for 18" and 19" sizes and I personally know it handles much better on 18" wheels with proper tire sizes. Unless you just like the bling bling Dub looks of 20's and don't care about handling.

The car came with 20 in Champion, pretty nice, wheels. I figured there was a
reason the 991 TT went with 20s. I guess we could all go back to 15 in Fuchs.

Thought about swapping out for 19s but would probably lose quite a bit on the
Champion 20s.

the car was designed for 19" wheels, the suspension geometry, alignment specs etc.. if youre not driving the car aggresively then youre fine...

as far as tire sizes... a 325 25 20 will fit the rear. the reason it will fit the rear is because the sidewall is sooo short that the wheel wont get "bubbly" at the edges...

lets say you had a 19x11 wheel, a 325 30 19 would NOT fit because theres too much sidewall.

many of us came from 996s with plus sized 19x11's running a 315/25 tire with absolutely no issue whatsoever...


your fronts should be a 245 30, rears 325 25. anything else will roast your front diff QUICK !! GUARANTEED !!


and remember, not all tire manufactors speak the same language.. a jap tire will run narrower than a michelin/conti

i'de suggest a set of nitto invo's. they are good tires, look great, are relatively quiet, and will definately fit your set up.

any pics of the champions ?

And the 996 TT was designed for 18s, owned a 2005 TT, and everybody went
to 19s as you say. As I said, thinking of swapping for 19s but it would
probably be a waste of a nice set of wheels. Other posts I have read where
guys went from 19s to 20s and said there wasn't much difference, Tire Rack
told me the same today as far as ride quality goes.

stick with 20s, but just make sure to get the right size.. 245 30 / 325 25.

Yea, this is what it looks like with the wheels, painted to match, think I'll
just keep them.

Keep them, looks great!

i agree. they look really good, but even in those pics you can tell something looks slightly off (that rear tire isnt a 325 its a 305), and im not guessing that from the width, im guessing it from the sidewall height... those extra few mm of sidewall make a huge difference.

is that your actual car ? if so she looks GREAT (with the exception of that stock front lip )

Yep that's the car. The lip does have a few whiskers on it. And, I think the
Advans on the car are 305 rears. I am going to end up with PSS in
245/30-20 front and 325/25-20 rear after talking to both Tire Rack and
Champion.