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recommended tire pressure for a 99 LS

Posted: Tue Jun 12, 2007 2:50 pm
by phantom444
The recommended tire pressure data inside the driver's door of my 99 Astro LS is unreadable. It's a stock eight-passenger with original-spec tires on original-equipment chrome slots. Can anyone tell me what the recommended front and rear tire pressure is for my van? Thanks...

Posted: Tue Jun 12, 2007 3:16 pm
by e7ats
I inflate my tires to the rating on the side of them.

Posted: Tue Jun 12, 2007 3:32 pm
by Jboy2
e7ats wrote:I inflate my tires to the rating on the side of them.
Agreed O:)

Posted: Tue Jun 12, 2007 3:52 pm
by tbhager94
35 - 40 psi cold is what most tire manufacturers suggest.

Posted: Tue Jun 12, 2007 4:33 pm
by phantom444
I know what the tire manufacturer suggests (35psi). What I need to know is the vehicle manufacturer's recommendations, usually different from the tire manufacturer suggestion, and different for front and rear. It's on a plate along the door jamb, along with gross vehicle weight, axle capacities, and manufacture date. As I posted earlier, this info is unreadable on my van.

Posted: Tue Jun 12, 2007 5:03 pm
by e7ats
My 94 says 35 and the 03 says 38. But if you put after market wheels on then that pressure may not apply.

Posted: Tue Jun 12, 2007 5:16 pm
by Jboy2
My 1990 astro says 35

Posted: Tue Jun 12, 2007 5:29 pm
by Water Boy
The manufacturer would list less than the tire manufacturer because the vehicle manufacturer wanted a softer ride by suggesting less PSI.

Since my 'stro is always overloaded, I run the sidewall max.
On my wife's Lumina, I run the sidewall max on the front and 5 less on the rear. Which is what I usually do on front wheel drive cars.

My 2 cents worth...

Posted: Mon Jun 18, 2007 11:17 pm
by Matrixx
Hi phantom444
I have the P215/75-15 tires on mine which is factory spec and in my 1996 manual it says 29 psi all around. That's with a 5-bolt setup.
Hope this helps.

Posted: Mon Dec 10, 2007 1:37 am
by motorvator
Sorry Guys, I have to step in on this thread.

Tyre(tire) pressures recommended for a specific vehicle have nothing to do with what is printed on the sidewall of a tyre. Tyre manufacturers, with a few exceptions, make tyres for general use and consequently the same size tyre can end up on all types of vehicles. The sidewall pressure is the tyre manufacturers max' pressure. Sometimes they have both min & max.

The poster is correct, the ONLY reference that should be used is the manufacturers plate on the door jamb, sometimes on the fuel flap or on the inside trunk lid of some sedans. Depends on the maker. It will identify the tyre size and cold tyre pressure. In some cases they will give another reading for when that vehicle is fully loaded. Depending on the type of vehicle, that recommendation could also have different pressures from front to back.

Manufacturers go to considerable lengths, racking up thousands of miles testing their vehicles under load for the purpose they were designed and with consultation with the tyre company who is supplying OEM make the recommendation that is placed on that sticker.

In the event you have changed the tyre size, all bets are off, the door plate sticker no longer applies. However, most of the tyre companies have excellent online resources to compute what the correct pressure should be for the revised tyre.

Tyre pressures are absolutely critical, if you over inflate you have decreased the footprint, you ride on the centre of the tyre. If you under inflate, you again have decreased the footprint and are riding on the sidewalls. If you let air out for "comfort" or add air for "performance" you have compromised the footprint and seriously jeopardised the handling of the vehicle.

Now imagine what happens when you add winter driving and ABS, that's another thread?

By the way: what is "cold" when manufacturers specify it? It is generally accepted 72degrees. So it leads to another question, eg: if tyre pressure is stipulated as 30 and you live in the Northern states or Canada during winter, what is the true amended pressure resulting from the cold?

The answer to that and all I've mentioned can be found at the main name brand tyre company websites.

Hope this helps.

As for my 1999 Safari AWD SLT: 35 front, 35 back

Re:

Posted: Sun May 29, 2011 3:24 pm
by astroturf
motorvator wrote:Sorry Guys, I have to step in on this thread.

By the way: what is "cold" when manufacturers specify it? It is generally accepted 72degrees. So it leads to another question, eg: if tyre pressure is stipulated as 30 and you live in the Northern states or Canada during winter, what is the true amended pressure resulting from the cold?

The answer to that and all I've mentioned can be found at the main name brand tyre company websites.

Hope this helps.

As for my 1999 Safari AWD SLT: 35 front, 35 back
Wrong, Wrong, Wrong...

Have a look here: http://www.tirerack.com/tires/tiretech/ ... techid=147

Hope it helps some, Jim

Re: recommended tire pressure for a 99 LS

Posted: Mon May 30, 2011 4:50 pm
by MountainManJoe
Here ya go.

Re: recommended tire pressure for a 99 LS

Posted: Mon May 30, 2011 5:35 pm
by astroturf
Man, I love Rule 6b...

Thanks Timeless

Jim