Tire size confusion... 1989 S4
02-22-2011, 06:12 PM
#31
Supercharged
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Is your car lowered? If so - 235 will not work on the front as it will rub.
I run 235/40/18 front (with rubbing) and 278/35/18 rears (no rubbing and NO spacers) - Nitto NT01's
ATP Rivas - Dunno the offset
Found these on tire rack
http://www.tirerack.com/tires/tires....um=735WR8DZ101
YMMV
I run 235/40/18 front (with rubbing) and 278/35/18 rears (no rubbing and NO spacers) - Nitto NT01's
ATP Rivas - Dunno the offset
Found these on tire rack
http://www.tirerack.com/tires/tires....um=735WR8DZ101
YMMV
We need context.I run 235/40'18's up front and they don't rub - but then I'm running a 57mm offset on my front wheels.
finally!:
One thing you should know is that the 91GT (like what I have - and what the calculator is based on) has a factory rolled rear fender lip. I believe that started in '89, '90 for sure. If you look at you rear tire arch and if the sheet metal just makes a 90° bend (instead of a 180°) then you'll need to allow for that. I think you'll be fine, but there are a lot of variables when it comes to tires on our cars. Tires vary from manufacturer to manufacturer, plus our cars were HAND-BUILT which leads to its own variances.
Hope this helps.
06-14-2011, 08:24 AM
#32
Pro
After much help from many here and ESPECIALLY Andrew O's incredible spreadsheet wheel fitment calculator only had one more thing to solve..
S P A C E R S
Of course this brought up a whole other issue, removing hubs, having to replace wheel bearings, etc., etc. So, after a few hours searching found some threads on Pelican and here related to the exact same wheels I have (Porsche Sport Classic II's) and spacers. Lo and behold Porsche makes a spacer which does not require installing new studs. Called local Porsche store and amazingly they had a pair of 17MM ones in stock which according the Andrew's spreadsheet will work!
Was lucky that one of the posts on Pelican even had a pic which included the part number! Picking them up tomorrow..
Many of you may already know of this solution but I did not so if duplicating something, apologies... I'm just happy to have found a solution which doesnt require a ton of work replacing the studs themselves!
Now of course paranoia is creeping in that someone here will post a reply saying NO NO NO!
S P A C E R S
Of course this brought up a whole other issue, removing hubs, having to replace wheel bearings, etc., etc. So, after a few hours searching found some threads on Pelican and here related to the exact same wheels I have (Porsche Sport Classic II's) and spacers. Lo and behold Porsche makes a spacer which does not require installing new studs. Called local Porsche store and amazingly they had a pair of 17MM ones in stock which according the Andrew's spreadsheet will work!
Was lucky that one of the posts on Pelican even had a pic which included the part number! Picking them up tomorrow..
Many of you may already know of this solution but I did not so if duplicating something, apologies... I'm just happy to have found a solution which doesnt require a ton of work replacing the studs themselves!
Now of course paranoia is creeping in that someone here will post a reply saying NO NO NO!
06-14-2011, 09:10 AM
#33
Drifting
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OK, wheels are on their way and wanting to order tires for them so as to eleviate downtime..
Wheels are:
Front: 18 x 7.5 50 offset
Rear: 18x10 Offset 65
According to the spreadsheet Andrew Olson created at
http://members.rennlist.com/andrewmo...01-24-2008.xls
I will need to put a 15mm spacer on the rears and then the correesponding tire sizes should be:
Front: 225/45/18
Rear: 295/30/18
BUT.. in between being referred to the spreadsheet by someone here I had emailed TireRack, they replied:
"The tire sizes we recommend for these wheels are 225/40 18 front and 265/35 18 rear. Anything wider than 265 on the rear will most likely require fender modification, otherwise it will rub ."
I did tell them the year, model, etc. and have used TireRack numerous times in the past but am concerned over the large disparity in recommendations on tire sizes.
Thoughts?
Wheels are:
Front: 18 x 7.5 50 offset
Rear: 18x10 Offset 65
According to the spreadsheet Andrew Olson created at
http://members.rennlist.com/andrewmo...01-24-2008.xls
I will need to put a 15mm spacer on the rears and then the correesponding tire sizes should be:
Front: 225/45/18
Rear: 295/30/18
BUT.. in between being referred to the spreadsheet by someone here I had emailed TireRack, they replied:
"The tire sizes we recommend for these wheels are 225/40 18 front and 265/35 18 rear. Anything wider than 265 on the rear will most likely require fender modification, otherwise it will rub ."
I did tell them the year, model, etc. and have used TireRack numerous times in the past but am concerned over the large disparity in recommendations on tire sizes.
Thoughts?
I think a different set of wheels should be an upgrade, not a downgrade from stock. And yes, 18" tires are not cheap either...
The grip (and balance) you have on the road is a really big deal, and good wheels (with good 928 offsets) and tires are a cheap and necessary upgrade in performance.
06-14-2011, 10:02 AM
#34
Carl, if he's pushing his car hard enough to have the issues you are talking about, he's got other worries.
06-14-2011, 10:22 AM
#35
Three Wheelin'
Thread Starter
And Carl, this was on old thread which was re-opened by another fellow who is looking to get wheels like mine. I can say I have had zero driveability issues whatsoever...
06-14-2011, 12:05 PM
#36
Nordschleife Master
06-14-2011, 08:24 PM
#38
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05-14-2012, 08:01 PM
#39
I'm throwing this on 3-4 popular wheel/tire threads since this seems to be a very confusing issue. I hope this helps someone out there.
*********************************************************************
I just scored on some Cup-1 wheels. ET52 7.5"-17 & ET47 9"-17
Tires I got were 225/45-17 ZR and 255/40-17 ZR. No problem fitting. Better ride than w/stock 16" 7 & 8" wheels. I'm sure you noticed TireRack.com has this exact size wheels and recommended tire size.
Cornering is fine. Didn't have to do anything special during install.
Also, I got good info while at tire store...this place has 800 locations, so I trust the info on the computer screen: (let me know if you need name of store, in case you need more MY details)
(This was for MY89, but I'm sure it will fit any applicable 928 with similar specs)
Recommended sizes:
7" ET46/55 / 205/225
7.5" ET48-52 / 205/225
8.5" ET47/49 / 225
9" ET47/55 / 245/255
9.5" ET52/56 / 255/265/275
10" ET45/50 / 265/275/285
*********************************************************************
I just scored on some Cup-1 wheels. ET52 7.5"-17 & ET47 9"-17
Tires I got were 225/45-17 ZR and 255/40-17 ZR. No problem fitting. Better ride than w/stock 16" 7 & 8" wheels. I'm sure you noticed TireRack.com has this exact size wheels and recommended tire size.
Cornering is fine. Didn't have to do anything special during install.
Also, I got good info while at tire store...this place has 800 locations, so I trust the info on the computer screen: (let me know if you need name of store, in case you need more MY details)
(This was for MY89, but I'm sure it will fit any applicable 928 with similar specs)
Recommended sizes:
7" ET46/55 / 205/225
7.5" ET48-52 / 205/225
8.5" ET47/49 / 225
9" ET47/55 / 245/255
9.5" ET52/56 / 255/265/275
10" ET45/50 / 265/275/285
