Tire pressure. Door or tire?

[Cliff5550]

Our newly-purchased 2004 has P205/50R16 tires and not the 55R16s on the door jam sticker. The door jam says to run at 34 psi but the tire sidewall says 43 psi. Big difference. I've been runnng at 34 psi but the tires, primarily the front, always look extremely under inflated and flattened out.
Suggestions? After a bit of reading I'm considering splitting the difference and running the tires at 38 psi. Thoughts? Suggestions?

[mole]

i would go with what the tires states on them.

[stan6406]

Most tires have multiple applications so what's on the tire is the maximum pressure for the tire. The pressure listed on the door is what is recommended for that car. Always go with what's on the sticker on the door or what's in the manual.

[pluminator]

Originally Posted by stan6406

Most tires have multiple applications so what's on the tire is the maximum pressure for the tire. The pressure listed on the door is what is recommended for that car. Always go with what's on the sticker on the door or what's in the manual.

Unless you have odd sized tires.

Try putting 32lbs in tires on 17" rims..........it wont be pretty.

What i usually do is look at the tire, AND the door. if they match, sweet.

If the door says 32psi and the max load is 28, i put 25 :-)

Just dont over fill them, youll be able to feel if you underfill them :-)

[NitroPT]

The Tire pressure is what most of us that do performance driving go by. i.e. my F1's are 50psi max rated my door jam say 35psi max. If I were to run 35psi max and compensate for heat expansion I would be all over the road on turns because of under inflation. That would be over 27% less then the maximum tire pressure. The tire would also wear on the outside portion of the tire. Now if I run 42psi the car will handle well and the tire will wear evenly.
You can always take chalk and draw a think line across the thread and then play around with different tire pressures to see what is the over all best pressure to use. Who knows it may turn out to be the "door jam jock" recommendation?


Naturally I have 4 cornered weighed my cars!

[stan6406]

Sorry. Somehow missed that part. I did go to the tire exchange calculator and it recommends not using this tire. Its outside the 3% size difference.

[pluminator]

Originally Posted by stan6406

Sorry. Somehow missed that part. I did go to the tire exchange calculator and it recommends not using this tire. Its outside the 3% size difference.

That tells me it was not put on at a tire shop. Odds are a second hand sale and the previous owner just didnt give a hoot.

[Cliff5550]

So I shouldn't even have the tires on that it came with? What is the 3% rule? Don't know if I can cover the cost of 4 new tires right now. Hazzards of keeping on what I have a little longer?

[Busted_PT]

Originally Posted by mole

i would go with what the tires states on them.

A man brother! I see a lot of excessive outer tire ware, when they go by the door.

[Busted_PT]

Originally Posted by Cliff5550

So I shouldn't even have the tires on that it came with? What is the 3% rule? Don't know if I can cover the cost of 4 new tires right now. Hazzards of keeping on what I have a little longer?

Don't worry about it . You may be showing that your going a tad faster than you actually are. You should see what ROCKETMAN is running for tire sizes.