tire pressure advice

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May 19, 2008 | 09:08 PM

#16

ididntdoit99

Elder User

Joined: Sep 2007

Posts: 700

Likes: 1

From: waterloo, iowa

Quote:

Originally Posted by jimm66

The maximum pressure on the sidewall is what the tire can handle safely. It has nothing to do with what the vehicle can handle. The door post gives you the pressure that is optimum for the vehicle.

Absolutley correct... The marking on the side of the tire is the MAX pressure for the tire, which would only be used when the MAXUMIM weight alotted for that tire is applied.

Quote:

Originally Posted by mjunk1

So I'm still a little confused, but I think this is the summary:

1. Start by checking door jam to see what the factory recommendations are - these will vary depending on the vehicle, it's GVW, etc. - as that provides a good starting point.
2. Check the sidewall of the tire to determine the maximum load - going over that is bad and possibly dangerous.
3. Grab a piece of chalk and mark your tires as described in the inflation post (#4) to get the best practical read on inflation levels.
4. Consistently check inflation as temperature, time, and other factors constantly change your inflation.
Sound right?

The chalk thing is mainly for if your change your tire size, then the door jamb number is no longer correct. Also if you carry extra weight, like a heavy duty bumper or toolbox, You would want to use this method instead of using the number on your door jamb.

Correct tire pressure is achieved when the tire rides completley flat on the road, so when different weights are applied (different vehicles) they will need different pressures to ride flat on the road.

Fortunatley, car manufacturers figure out this numbver for you and write it on the sticker inside the door jamb, glovebox, or fuel door.

Now if you adjust your tire size, or carry alot of extra weight, you need to figure out those number yourself. Simply take a piece of chalk and mark across your tire, now drive a couple of feet and look at the chalk line, if it wear off in the middle faster, you have to much pressure, if it wears on the outsides, underinflated.

Keep trying until it wears off evenly, and remember to do the front AND back because they will be different. Also a good thing to do quickly when you haul a large load.