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Expected Tire Life

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Old 09-08-2004, 01:37 PM
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Gino
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Default Expected Tire Life

Have done some searching on the Forums for info on tire life/pressure without any real conclusive data.

Just how long (moderate street driving) should tires last on these beasts? Front? Back? Also, pressure?

I'm running Bridgestone 03s 225/50 up front 245/45 rear on 16" Fuchs. The fronts are fine with lots of life left at 32# pressure. The rears are showing tread bars in the middle. They both have 18K miles.

I'm aware that this could be some over-inflation on the rears (although the sticker says to put 44# on the back), but I'm doing this purposely to try to find the correct pressure. I'm running 40 on one side and 35 on the other and they both still show the same wear pattern and amount of wear.

I'm a bit concerned to go lower on the replacement set, but at what pressure have others been successful with to achieve even across the tread wear on the rear? And is 25K or 30K unreasonable to expect with street driving?
Old 09-09-2004, 12:18 AM
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turbocarrera.
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I use Yokohama A032R's and get about 2000miles out of the rears and about 6000 out of the front.. I run what my manual says for pressure 29/34, a little more if I'm going on a long high-speed trip.

S03's have a wear rating of 220 vs 60 for the Yoko's so I would assume you should get alot more mileage than I do but it all depends on how crazy you drive I guess.. 18k sounds great for the rears.. I think you're probably doing fine with the fronts too.. I don't think 5psi would make a huge difference in wear but it should make some, enough to notice.. might depend on whethere you take lots of left or right corners? alignment or corner balance? bah I dunno..
Old 09-09-2004, 12:56 AM
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fixnprsh
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hmmmm.......lets see, when a 930 (let alone one with mods) is on boost...the front tires have about the same weight on them as your hand does holding a box of Cheez-itz...so if your a lead foot, expect one set of front tires to every 10 sets of rears, light foot about 1 set front to five rears

Who cares, you dont buy a Porsche (especially a 930) for tire wear, so as a Nissan owner would say "enjoy the ride"
Old 09-09-2004, 08:19 AM
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morganb
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Tony,

Geez, only 2000 miles!! Is that all on the track or also on the road? I would love to get some more input on others on this. My turbo has about 25,000 KM's on it (all road I understand) and I was a bit worried they might be the original tyres. If people only get 2000 miles I need not be worried!!
Old 09-09-2004, 10:46 AM
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Gino
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fixnprsh-
you must have had a rough day, or a tough evening putting the kids to sleep... Ouch!

I'm more concerned about getting the most out of my 930, including wear evenly across the tread on all tires. After watching and reading how sensitive these beasts are to suspension set-ups on this (and the racing/ DE) forum, and since I've 4 wheel aligned, ride height adjusted and corner weighted this vehicle... I thought asking what may seem silly about tire life and pressure from those with experience would be good approach to potentially troubleshooting some overlooked issue.

In fact, a PM from someone indicated due to rotational/centrifugal forces, center wear can actually be caused by insufficient pressure to hold the tread square.

If you have constructive comments, please feel free to make them. Otherwise, injecting humorless comments does not promote the P-breed.
Old 09-09-2004, 03:32 PM
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turbocarrera.
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All street driving, Bruce. R-compound tires grip well but wear out fast.. and they only come with 6/32" of tread depth when brand new.. I have been known to slide the car around alot too.. fun fun fun!
Old 09-09-2004, 11:45 PM
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fixnprsh
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oh no, no kids so im good, funny intentions only.
you can go through a gazillion tire pressure settings, alignment settings, driving style, tire compounds, etc in all combinations. you need to figure out what YOU do with the vehicle, if you do alot of auto-x, canyon runs and track days, then leave it on an aggresive set up (which I imagine you do these after all you've mentioned) with some DOT legal R compuonds and enjoy it and live with the tire wear. however if you drive it easy on the street, a set of Yoko's AVS family tires will wear perfectly fine for 20,000+ miles and still put up with the occasional canyon run. look up reviews of tires at THE TIRE RACK
I have Yoko AVS ES100's on the GTI with -2 degrees of camber and they have been there for 8k miles and still have half their tread after regular canyon trashings and hard driving.
as far as them wearing in the middle, to the tread bars, this seems to be the norm on most 930's ive seen and running too much pressure will add to this. If it were my car with all the mods you have described i would put on a tire like the Yoko A032R and in your rear size is $191 a piece, they give serious traction and can last 10K miles, they are noisey for the street but when people see the tread they know your car means business and can back it up.
Old 09-10-2004, 09:32 AM
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Gino
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fixnprsh-
thanks for the constructive comments. a few things...
not too many canyons to thrash here around Boston, unfortunately. plain driving is an adventure!
my 930 has absolutely no mods, bone stock, just attention to specs. was an addict in the 70's.
I do a lot of high speed highway driving and suspect my rear tires bulge or crown from speed. therefore the center wear, and not over inflation as my pressure is set well below the recommendation of 44#.
maybe I should re-think brand of tire, the Yoko's or Kumo's may be too radical for my style of driving and perhaps I picked the wrong Bridgestones... maybe the RE750's instead of the O3's suit better?. Or, Michelin Pilot Sports or the Dunlop SP9000's?
Perhaps someone else on the forum has similar driving style/ car set-up with a recommendation?
Old 09-21-2004, 07:46 PM
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Default Expected Tire Life

I ran Michelin MXX3s and only got about 4,000 miles out of them but my front toe in was off causing wear on the inside edge of the front tires. I went back with Michelin Pilot SX's. I think they are great tires and a huge improvement over the MXX3s. I really like the Pilot SXs and am going to put them on the 951 also. I have also heard a lot of good things about the Kuhmos but have never put them on any car. Good Luck!
Old 09-22-2004, 02:13 AM
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justkickenit
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My car is bone stock except for the wheels, and I think Gino and I probably have simular driving habbits as I'm either commuting in the car or on weekends I'll get it up to about 100MPH coming off of page mill road - just to let her breath a bit.

I have Bridgestone Potenza RE750's. 205/50 in front, 275/40 in the rear. Handles great and is quieter than the tires I replaced, Dunlop SP9000. I have about 5000 miles on them and so far there is no sign of significant wear. In addition they seem to be wearing evenly.
Old 09-22-2004, 08:40 PM
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Gino
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Justkickenit-
probably similar habits... I just got the beast back from the wrench. He's very happy with the tire wear and mileage. Here in New England, Direct Tire is well respected. They are pushing Toyo T1-S for my car. Any word on these? I'm almost certain to buy the RE750 for the rear, and when it's time the front too.

He was also fixing my cold start problem... dead ThermoTime switch, clogged Cold Start Injector, one Fuel Pump half alive and the other over worked. Replaced it all, and the relays too... viola!

Along with that fix, a full tune was done; don't get me wrong, it's better than before. He also removed all my air injection stuff, fixed oil and vacuum leaks. The car is much more responsive.

Though, I think there's something else going on... between 3-4 grand in 2nd or 3rd (not as noticeable in 4th), on steady gas pedal pressure the car seems to be surging. I can see the tach move up/down to the feeling. Could that be fuel pressure? Is there a regulator? Or, could it be a bad plug or wire? Ideas anyone?



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