Correct Tire Pressure?
Thread Starter
Instructor
Joined: Sep 2005
Posts: 161
Likes: 0
Correct Tire Pressure?
Just took my '04 Vert to my mechanic for brake fluid change and when we pulled the tires, noticed wear on the inside. Suspected incorrect toe-in, but when we checked, it was spec... Mechanic asked what tire pressure I run? I said 30..as it says on the door. And he said (he used to be a racing mechanic and had lots of dealings with tire mfgs) that the inflation recommendation on the car is not what you should run, but rather closer to the tire mfg's recommendation... which, of course is max 40+ psi. These are stock Goodyears with 18k on them. Of course if you put 40psi in the tires, the sensors tell you that you are overinflated (duh)... I always knew about wear on the center (overinflated) and outsides (underinflated), but I don't know exactly what to do if the alignment is at spec and the tires are wearing on the inside? Does anyone run dramatically over the recommended 30 psi? ...and with what results or does anyone have a "your mechanic's an idiot" answer....or?
Melting Slicks
Joined: Feb 2007
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From: Indian Rocks Beach FL
St. Jude Donor '08-'09-'10
Your mechanic is a first class BS artist! You should be running 30 just like you are. The wear you are experiencing is not from toe but most likely from camber. I would not be taking my car back there ever.
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From: Warrington Pa.
And I'd take it to another alignment shop and have them do a 4 wheel alignment.
Race Director
Joined: Jul 2004
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From: Lake Havasu City, AZ
30 psi cold is correct....
Your mechanic may be right about the air pressure they ran at the track,on their racing tires, but he is wrong about the correct pressure for the street.
Your mechanic may be right about the air pressure they ran at the track,on their racing tires, but he is wrong about the correct pressure for the street.
Drifting
Joined: Jan 2008
Posts: 1,549
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From: Cambridge Illinois
30F and 30R. That is what you should run. 40 psi is wrong. The center would wear out fast and wet traction and cornering would be poor.
That was the most dumb a-s recommendation I have ever heard.
That was the most dumb a-s recommendation I have ever heard.
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From: Fort St John B.C
Yup. Corvettes (C5 anyways) are set aggressive from the factory with a bit of neg camber.
Tech Contributor
Joined: Dec 2003
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From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
It just goes to prove that being able to go fast doesn't make him smart. Even on a racing car you'd want max tread on the surface. Over inflation would surely reduce that.
The figures on the door are based on the car not the tire.
Some Michelin owners get center wear (over inflation) even running as little extra as 32 psi.
The figures on the door are based on the car not the tire.
Some Michelin owners get center wear (over inflation) even running as little extra as 32 psi.
Last edited by DeeGee; Apr 14, 2010 at 02:39 AM.
Pro
Joined: Dec 2009
Posts: 719
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From: Columbia South Carolina
The wearing on the inside of the front tires is NORMAL, the specs for a corvette are just that, ZO6's are even worse.
It's just amazing that people always think that they know better then the manufacturers when it come to the tire pressure. Race and track cars are one thing, but street is another. Since it's printed on the car. And that other pressure on the tires does not say RECOMMENDED but MAXIMUM TIRE PRESSURE..........Duhhhhhhhhhhh......... ...Ya want to slide around the street like a wet dog on a waxed floor, then go ahead put 40lbs in the tires.....
GET RID OF YOUR MECHANIC.
I rate this----------------POSSIBLE USER ERROR--------------------------
It's just amazing that people always think that they know better then the manufacturers when it come to the tire pressure. Race and track cars are one thing, but street is another. Since it's printed on the car. And that other pressure on the tires does not say RECOMMENDED but MAXIMUM TIRE PRESSURE..........Duhhhhhhhhhhh......... ...Ya want to slide around the street like a wet dog on a waxed floor, then go ahead put 40lbs in the tires.....
GET RID OF YOUR MECHANIC. I rate this----------------POSSIBLE USER ERROR--------------------------
Burning Brakes
Joined: Oct 2003
Posts: 1,106
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From: Foresters Falls(near Ottawa) Ont
With the camber set to "zero", the tires won't wear on the inside. The car will still steer and handle like it's on rails!
RonJ ...
Burning Brakes
Joined: Dec 2009
Posts: 842
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From: St Paul, MN; Orlando, FL
FWIW, I just put a set of new tires on and I must have reviewed about a bazillion opinions on various threads here about tire pressure. Conclusion: 30 front, 29 rear, frequently test with a good gage and only adjust if necessary.
Instructor
Joined: Jan 2004
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From: Loughborough, UK
I have 245/35/19's (front) and 285/30/20's (rear).
After a professional alignment setup I run 34psi front and 36psi rear and my car handles like a sports car.
The technician at the garage laughed at the settings for toe in and camber I had been given
(they deal with supercars day and night), I was happy to leave the car in their judgement and was not dissapointed.
Amazing outcome, I can pull the figures out if anyone is interested?
After a professional alignment setup I run 34psi front and 36psi rear and my car handles like a sports car.
The technician at the garage laughed at the settings for toe in and camber I had been given
(they deal with supercars day and night), I was happy to leave the car in their judgement and was not dissapointed.Amazing outcome, I can pull the figures out if anyone is interested?
Race Director
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From: Indianapolis IN
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17
Your mechanic is a moron. The 40+ on the tire is a max pressure to not exceed. Do as others have said and run the car manufacturer recommendation, fire your mechanic, and move on. He may know what is going on under the hood, but is absolutely clueless when it comes to tires.
Race Director
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From: SE Pennsylvania
St. Jude Donor '03 thru '26
Oldtimer
The guys who built these cars went to great length's to make sure they covered everything. If they say 30 PSI, thats what is the best air pressure. Anybody who owns a C5 should read, "All Corvettes are red" by James Schefter. You get a real world education on how the C5 Corvette came about, how the new LS engines were developed, the 'New' state of the art tires, the most important thing, the computers work, and a lot, lot more.Lately Toyota has had some problems with it computerized engine control ? GM was doing critical PCM program writing the dead of winter in northern Canada at 40 below, then taking the same cars and computers to Arizona to see if the programs in the PCM could stand up in 130 degree weather. And since no Covette since 1997 has anything connection to the engine compartment other than a wire loom, I'd say they got it right. Since I've never heard of a single C5 Corvette with 'Unintended Acceleration' problems ! I put 30 PSI in my tire at the end of the winter storage with my little 100psi air compressor and it rides great !
General Motors built a great car !
