cold_beer839

I just bought a set of 18" Carrera wheels 18 X 8.0" front & 18 X 10.0" rear.

See the wheels at this link:
http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=006

What size tire is recommended on these wheels?
My '87 928 S4 has the stock ride height.

I was thinking 235/40/ZR18 front and 285/30/ZR18 rear (or 265/40ZR18 rear).

Please give me some input.

Thanks,
David

Bertrand Daoust

Nice wheels
Take a look at Andrew's Wheel Fitment Calculator. It might help you.

http://members.rennlist.com/andrewmo...01-24-2008.xls

Hilton

You might want to contact the seller, and see if you can either:

• Switch these wheels for 18" Carrerra III (997) wheels. Also 18x8 and 18x10, but in better offsets for the 928 (ET57 front, ET58 rear).
• Cancel the transaction and get C III's elsewhere

I think I've seen that vendor selling Carrera III wheels before, so even tho' they don't list any currently on Ebay, they might be able to do the switch. The carrerra III's are a very similar 5-spoke design.. they're the 997 equivalent to the ones you got (which are the 996-offset version).

If you can't do either option, its not a disaster - its just that the front's are a slightly too low offset, so they'll stick out from the fender wall at the front, and you might experience some tram-lining.

Stromius

I run 225/40/18 front and 265/35/18 on the back (contisport) on 993 18 x 8, 18 x 10. I plan to move fronts down to 205 or 215 (if they exist) to reduce tramlining in ruts on the freeways especially. Not sure it'll help.

DonT

With the Carrerra III wheels -

What is the best size tires for a MY '87 S4 (front & rear) without having to roll or modify the fenders?

rixter

not a good idea, 225 front MINIMUM on a 928

IcemanG17

With the 18x8x50mm front wheels a 225/40 tire is the the widest that will clear and not rub....I have the Carrera III's and run a 235/40 on the front at slightly low ride height (155mm) with no rubbing at all....with either rear rims you can run up to a 285 rear tire no problem.....I heard up to a 295/30 rear with the Carrera III's with no rubbing...but thats gotta be tight...

DonT

Brian -

Thank you for the info.

FlyingDog

Agreed. Do not go below 225 in the front. Not only will steering and braking suck, you will be on the very low end (if even acceptable) for an 8" wheel.

IcemanG17

If you want to roll the rear fenders a bit......then you could run up to a 315 or larger no problem...BUT you need a wider rim to do it...295mm is the max for a 10" rim...just like how 235mm is the max for an 8" rim BUT they do make a 11" CIII rim.....I think its a 51 offset which makes a perfect 8" backspacing, which works great on the rear of 928's.....an 11" rim could run up to a 325mm tire...

Erling G-P

I have 265/35-18 on my rears, and I believe these are actually slightly larger in diameter than the stock wheels/tyres, so you probably wouldn't want to go with 265/40-18.

Cheers,
Erling

FlyingDog

245s are fine on 8x18 wheels. http://www.tirerack.com/tires/Spec.j...irePageLocQty=

cold_beer839

Ok, I switched to the Carrera III (997) wheels.

Thanks for catching that offset difference.

Here is a link showing several 928's with both wheels: http://www.wheeldynamics.net/Gallery.html

I should end up with this stance with the 997's on my S4 (I know that is a GTS in the pic):

ShawnSmith

Nice!

cold_beer839

I found a tire size converter online:
http://www.s-series.org/htm/calc/tiresizeconv.htm

If the stock rears are 245/45ZR16 and are 24.7" in diameter

Then 285/30ZR18 is 24.7" in diamater also. They would be better for retaining speedometer calibration.

Will the the 285/30ZR18's rub in the rear? They are 11.2" wide according to the calculator.