tire psi

[drunkrusski101]

Hey I have a 2007 si sedan, and I think my tires are low on air, on the door it sas it has to be 33 psi on the front and rear, but on the tire it sas it has to be 44 psi. so whats the pressure on the front tires?

[fishermoe14]

if your riding stock tires, use the door number

[NBPRudy]

44psi on the tire is a maximum pressure.

[rmfa]

I changed my tires and was wondering what I should run. If your NOT running stock tires, what is the recommendation?

[NBPRudy]

It will say on the tire.

and your joking right??

[jackolee]

the number on the tire is the maximum psi
just put it at like 35

[rmfa]

Originally Posted by NBPRudy

It will say on the tire.

and your joking right??

It says the max on the tire, right?

[cypress]

mine are 32 psi with stock 16" tires.

[jthoske]

I checked my tires the day I took ownership of my car and they had 35-36 PSI cold in them.

I dropped them all down to exactly 33psi.

[NBPRudy]

Originally Posted by rmfa

It says the max on the tire, right?

Umm yeah for a second I was thinking it would say both.

Anywhere betwween 32-35 is good.

[MikeDawg]

Originally Posted by jthoske

I checked my tires the day I took ownership of my car and they had 35-36 PSI cold in them.

I dropped them all down to exactly 33psi.

That seems a little extreme. If the tires can safely handle 35-36 psi (below the max pressure for tires, as I can only assume it is), you're not going to hurt anything by running them at a very slightly higher pressure.

[etcthorne]

Agree with using manufacturer's pressure recommendation if running stock tires. That number will always be below the max pressure the tire will allow (written on the sidewall). That number is what the engineers caculate will allow safe operation of the vehicle and maximum tire life.

Remember that if you choose to run max pressure, like that stamped on the sidewall, your tires have no more capacity to safely hold the increased pressure that happens as your car is driven and tires heat up.


If anyone doesn't believe this, measure your tire pressure cold, and then measure it after you've been driving for a while.

[rmfa]

Originally Posted by etcthorne

Agree with using manufacturer's pressure recommendation if running stock tires. That number will always be below the max pressure the tire will allow (written on the sidewall). That number is what the engineers caculate will allow safe operation of the vehicle and maximum tire life.

Remember that if you choose to run max pressure, like that stamped on the sidewall, your tires have no more capacity to safely hold the increased pressure that happens as your car is driven and tires heat up.


If anyone doesn't believe this, measure your tire pressure cold, and then measure it after you've been driving for a while.

My question was: What if you are NOT running stock tires? How do you know what to set your PSI at???

[NRM]

If you aren't running on stock tires, you're going to have to use your judgment. The sticker only really refers to the tires that came with the car. A general rule is take the number on the sidewall of the tire and subtract 5-8PSI. The more precise is 80-90% of the total tire PSI.

And here is the chalk test.

To check if your correct take a piece of chalk and mark a line across the tires in one spot. Drive about 20 feet and see where the chalk rubbed off, if it rubbed off almost consistently through the entire line then you have the proper inflation, if it rubbed the edges off your under inflated and the wheel will eventually become cupped (outer treads wear off faster), if the inner wears off your overinflated and the middle will wear away faster.

[ryker]

I've always used max psi in my tires. Keep a high quality tire gauge in my car and check it at least monthly. Gives better MPG.

[MikeDawg]

Originally Posted by ryker

I've always used max psi in my tires. Keep a high quality tire gauge in my car and check it at least monthly. Gives better MPG.

I think high quality tire gauges are a misnomer. I think the most I ever paid for a tire gauge was $20, for a decent electronic gauge, and it quit reading the right psi after a couple of months.

What is the secret to finding a good, quality, and long-lasting tire gauge. I've had everything from the $0.50 plastic "standard" gauges, $2.00 plastic round gauges, to the $5-$20 metal round and standard gauges, and they all fail in less than 6 months.

[Mateen]

If you go 85% of the sidewall max, you will have the ideal pressure and good gas mileage.
For example, the stock max pressure is 44 psi. I have mine set at 37 psi.

[ryker]

Originally Posted by MikeDawg

I think high quality tire gauges are a misnomer. I think the most I ever paid for a tire gauge was $20, for a decent electronic gauge, and it quit reading the right psi after a couple of months.

What is the secret to finding a good, quality, and long-lasting tire gauge. I've had everything from the $0.50 plastic "standard" gauges, $2.00 plastic round gauges, to the $5-$20 metal round and standard gauges, and they all fail in less than 6 months.

I get the gauge that has a flexable hose and a gauge on the other end. Major function is it has a bleed off valve so I can over fill the tire and bleed it down to perfect psi. Might have cost me 15.00

[ryker]

Originally Posted by Mateen

If you go 85% of the sidewall max, you will have the ideal pressure and good gas mileage.
For example, the stock max pressure is 44 psi. I have mine set at 37 psi.

Having placed over 45k miles on the Honda Insight I can say for sure that the car required over 100% max sidewall psi. Nearly all of the hypermillers that I knew kept 50 or more psi in the 44psi rated tire (don't quote me on those numbers but it was well over max)


There are too many tires and driving habits to have "the ideal" psi.

[Zeuceone]

the stock si tirees lose air fast so check them every week.