SeanR

I think it's about time to treat Kibort like GhettoRacer. Give him his own forum and let him run rampant though it so he stops ****ing up every thread.

GlenL

"Stiff" like when you hit potholes and the car jolts.

Blather on.

GlenL

Check the overall diameter. You want one near 24.5". A smaller tire will give a higher speedo reading. A smaller tire will also make the car squat back a bit.

Mongo

I did not know you could fit a 245 tire on the front of these cars. Wow.

SeanR

Yep, been running that on mine for years and several around here have 255's and one guy with 265's.

mark kibort

no need to be rude Glen... but yes, stiff can make pot holes seem more jolting. BUT, a larger tire seems to mitigate the effects as well.

really? you have that much of a problem with information. ive tested almost all these combinations discussed... tire temps, wear patterns, etc. but you would rather hear from the bench racers? you are a piece of work... were you beaten as a child? just relax and take it all in. all im doing is providing information that I think can help. no one EVER has complained of the help ive provided on their 928s, especially to advice with tire size and fit.

Glen... have you checked your speedo for accuracy lately? trust me, its off anyway. in fact, it will be dead nuts on with a 26" rear tire, so there is some room to play with .
overall, the best tire sizes for the 8.5 and 9.5" rim would be the 255 and 275 combo. I have 10s of 10000s of miles on this combo with NO complaints or issues, wear, handling or anything else performance related.
however, on the small side, you could run the 245x40 if you have size limitations up front you are concerned with .

mark kibort

no problem with the 275s up front either...... that was done back in 1998 with deveks first set of rim designs 9.5 and 11s with 8" back spacing. no fit problems at all.

Cameron

Wheel offset it important to avoid rubbing. On my '87 S4, I went with the Panamera 18 inch 5 spoke wheels as per OP question. 8 in front ET 59, 9 in rear ET 53. 6 mm spacer in the back. No rubbing lock to lock front or rear, not that the back was a concern.

Tires - Michelin Pilot Super Sport. 245 35 Front. 265 35 Rear.

Pjmeyer

To the OP Dennisrh: I had to do a double take when you posted the picture - I have the same Panamera wheels, and Michelin tires in that same size, plus my car is GP white with tinted glass.

I'm very pleased with my decision and hope you are too.

Mongo

Sean, what wheels do you have on your car again?

hb253

Interesting point about spacers. I believe my 84 has spacers - 22 mm maybe? If true, then what are the chances I need to replace them with thinner ones to fit the 9-inch rims?

Hugo

SeanR

Kinesis K18's. 12" 295/30/18 38 offset rear, 9" 245/35/18 no idea on offset front. That was until a week ago now I just have some standard 18" Twists from a boxster that I bought for $250 until I get the Kinesis repaired.

mark kibort

thats a big rim for a 295, as an 11 fits up to a 315x30 perfectly, and 335 in a pinch and 10s are a perfect fit for a 295 or 305. you are two inches too wide. according to Jim, wrong fiits can become a problem, but on the street its not a big deal.

curious as to what your backspacing is on your 12s? as you know, i have K18s as well. mine are 11" with 8" backspacing.perfect for the rear of the 928 and up to 305... no spacers. but, if you do some nice bat work, a 17mm spacer can be used as well.

be interested to hear of the backspacing of your 9" front rim, as it can accomodate a 275 with no issues. 255 for sure.

mark kibort

i had the 84 with spacers too. there was no issues with the K18s and 11" rear rims and up to 295s. some massaging of the rear fenders was required. you can just take off the spacers if needed and run open nuts too.
i think i ended up machining down the spacers to 17mm so i could fit the 305 tire in the rear without any major fender work. (just some rolling)

FredR

Hugo,

255 was seemingly a popular section width with good availability for 17 inch wheels and 265 seems more common on 18 inch wheels for whatever reason. There is no reason I know of why you should not run with 255 on the rear end and in fact it is closer to the stock diameter of 25 inches than the 265 that is typically 25.4 inches.

Rgds

Fred