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Discussion Starter · #1 ·
when i got my tC i didn't think much of the tire pressure cause i figured the dealer had it covered..

then a week or two later i took out my trusty PSI guage and gave it a read.. and the front tires read 48PSI! i was like hmmm that's strange is my guage broken? cause i know from the manual and the sticker on the door sill says the front tires should be 32PSI.

so i figured it was a guage error.. few more weeks go by and i thought i'd check it again at a gas station and once again i got mid 40s.

so i guess my tires are really at a high PSI. i looked on the tire and it said the max PSI is 50, however the manual and the door sill says 32 for the front tires..

so which one do we go by? if 50 is on the tire and isn't 32 a lil low? cause reading the tire care manual it was saying all this stuff about how even a slight flunctuation in the PSI increases the heat exponentially...

so help a car newbie out and let me know which to follow
 

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Did you read the tires warm or cold? Check the pressure when the tires are cold. They should read close to 32. IF you like....maybe you could have your tires at 34. Mid 40's is asking for problems. Big blow-out type of problems.
 

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That's a little extreme, the tires won't explode unless you run them over the maximum rating with more than the maximum load at more than the maximum allowable speed. The tire manufacturer's learned their lesson with the Ford Exploders.

You're right about reading the tires cold. You should check them after the car has been "resting" for at least 8 hours out of direct sunlight for the most accurate readings.

However, in this case, even if everything were going wrong with the cold pressure, you should never see 40+ psi with a 32 psi cold pressure. Typical pressure rise is 4 - 6 psi from cold to hot.

Here's what will happen: the center of the tire will wear faster than the outside edges, so your tire life will suffer. Traction and control are also affected, but not nearly as negatively as being underpressure.
 

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Discussion Starter · #4 ·
well i've checked it cold and its still above 40... checked it yesterday and it read about 40 ...

so should i be letting some air out?
 

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I would. I'd take it down to the recommended pressure.
 

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Don't go 85+ MPH for long periods of time, or you're asking for blowouts, regardless of your tire pressure; overly high tire pressure just increases the possibility. "Maximum pressure" is exactly what it sounds like, and the same applies to "recommended pressure."
 

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I'd get on the dealer about having them so high at delivery. They should be held accountable if anything happens to them.
 

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Discussion Starter · #9 ·
well its been so long.. even if i called to complain tehre's not much they're gonna do or say.. except MAYBE.. HUGE MAYBE.. "sorry"

can't really prove that the pressure was high when i got the car so they'll jus say that i increased the pressure myself..

i'll let out the air and get it down to recommended level... hope my driving on the high psi hasn't ruined my tire life! GRRRR ..
 

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Originally posted by basilisk4@Dec 23 2004, 09:54 AM
Don't go 85+ MPH for long periods of time, or you're asking for blowouts, regardless of your tire pressure; overly high tire pressure just increases the possibility.  "Maximum pressure" is exactly what it sounds like, and the same applies to "recommended pressure."
No, that's just not true! Tires are tested at their maximum rated pressure with maximum rated load at their maximum rated speed. The tC is no where near the maximum load, and couldn't run at even 150 mph (V rating) continuously no matter how much you want it to. Stock tires are Z rated, even if the auto could pull redline in top gear you could not exceed the speed rating on the tires.

You are FAR more likely to blow out a tire with too low pressure than too high pressure. If the pressure is too low, the tread blocks move more, generate more heat, and are more likely to chunk (break off in pieces) because the rubber gets too soft from heat build up. That's what happened to the Exploders. Compounding this issue was a tire expected to last 80,000 miles. They were so durable that owners typically paid NO attention to them and after a year or so of neglect, they fragmented from overheating because they had less than 15 psi in them.

On the race track, we control tire temperature with pressure. Too hot, raise pressure, too cold, lower pressure. Heat destroys tires, not pressure.
 

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My car was delivered with high tire pressure too. The car road like a unsprung hay wagon. Like it has been posted...extremely low pressure is more of a problem for safety. I still advised dealer that the car was delivered at max. pressure..not the proper pressure. It appears that their prep guys read it on the sidewall and fill it that way. Not a good thing really. Tire wear and ride can suffer. Contributes to those new rattles too!
 

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Discussion Starter · #12 ·
yea i corrected my PSI today and went for a spin... ride, traction and control was noticeably smoother and better... i check it every few weeks just in case i have a weird pinhole somewhere that's leaking
but so far so good.... i'll be sure to keep it at the recommended psi from now... cause the ride is sooo much smoother
 

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Speaking of tire pressure issues, I had my tires rotated at the dealership the other day while my oil was being changed, and despite the fact that it took them 90 minutes to do a job which should have taken 30, I noticed yesterday that the idiots forgot to adjust the tire pressure...so my front tires were at 29 PSI and my rears at 32...Idiots.
 

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Originally posted by basilisk4@Dec 26 2004, 06:54 AM
Speaking of tire pressure issues, I had my tires rotated at the dealership the other day while my oil was being changed, and despite the fact that it took them 90 minutes to do a job which should have taken 30, I noticed yesterday that the idiots forgot to adjust the tire pressure...so my front tires were at 29 PSI and my rears at 32...Idiots.
Yeah..isn't service like that Great? I mean it makes you think about the value of getting any service performed anywhere. I have free scheduled service for 2 years or 24,000 miles. It consists of little more than oil changes and tire rotations. 3 of the oil changes are the 3 that Scion does anyway..that accounts for all of them up to 20,000 miles ay. If you have to go back and check what they did..the service is worthless.
 

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It's hard to get conscientious help for minimum wage these days.

Now you have to ask yourself, did they even properly torque the lug nuts?
 

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That's a scary thought.
 

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Originally posted by lo bux racer@Dec 26 2004, 11:02 AM
It's hard to get conscientious help for minimum wage these days.
[RANT]
you are actually touching on something that i've had a slight beef with for some time.



people really don't earn their paychecks.



and the people who do work hard, sometimes even above expectations, get the shaft and are not paid enough. [/RANT]

thanks.
 

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I heard your guys had a few false starts with bumper appliques, I know mine was one of them. It isn't rocket science, but some people figure they showed up for work so they deserve to get paid. It's a sad commentary.

Glad it's not universally true.
 

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Three cheers for labor unions! That's who we have to thank for many aspects of American laziness in the workplace.

P.S. Torque the lugnuts? Who cares about torque? Actually, I'm being serious, though -- I've never measured the "torque" which I apply when tightening a lug nut, and amazingly, no wheels have ever come flying off my car.
 

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No, the wheels won't fall off, but the brake discs can warp.
 
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