Tire Pressure


#1

This is all the rage these days, but what pressure do I use? The door jamb on my 2002 Chevy Trailblazer says 32 psi and the sidewall of my Peerless tires say 44 psi. Which do I follow?



Thanks


#2

Door jamb. The sidewall is a ‘do not exceed’ number.


#3

Go by the information in the vehicle manufacturer’s doorjamb sticker.


#4

The door jamb. The tire just gives the maximum pressure you can put in the tire, not what is best for your vehicle. You want 32psi, though I often run a little firmer (34 or so)


#5

The door jam…ALWAYS the door jam.

The number on the side wall only says the MAXIMUM tire pressure for that tire. It’ll also display a weight. Something like 44psi@1500lbs. These tires can be installed on many different vehicles with different weights. So the pressure will be different depending on what vehicle the tire is installed on.


#6
Go by the door jam number, but check the number of the tyre.  If that number of the tyre is [b] less [/b]  than what is on the door jam, those tyres are not safe on your car. 

Thanks to Tex I have corrected the above.  Yea, I wrote it backwards.

#7

Don’t you have it backward? You always want the number on the tire greater than the number on the doorjamb. That lets you use the recommended (door jamb) pressure.


#8

Maybe I have it backwards, I would go for the 44 psi knowing that gas mileage would be better, but the ride and traction would be worse. Heck if you need more traction let 4wd auto do it, you’ll probably get through fine but if you need more traction you could drop the psi down. My thought is if the tire is designed to be run at 44 psi you may end up with tire wear associated with an underinflated tire and additional sidewall stresses leading to failure. one quote I always remember is more tire failures occur due to underinflated tires vs overinflated tires and based on the fact the tire mfg recommends 44 I would choose it for me if I could stand the ride. This is an opinion of what I would do, do not try this at home, consult the tire manufacturer for their recommendation.


#9

The tire manufacturer doesn’t ‘recommend’ the sidewall pressure, that’s a warning to not exceed that pressure or the tire may burst. The vehicle manufacturer sized the tire and sets the pressure recommendation based on lots of factors, including ride, handling, and tire wear. Their recommendation is the only one available or appropriate.

Besides, there’s very little MPGs to be gained going over pressure.


#10

MY TIRE’S SIDEWALLS SAY 51 MAX PSI AND THE DOOR JAMB SAYS 32 PSI FRONT 28 REAR. BUT THE DOOR JAMB NUMBERS ARE FOR THE TIRES WHICH CAME WITH THE CAR. I RUN AT 44 PSI ON MY 51 PSI PERFORMANCE TIRES AND GET EXCELLENT SERVICE FROM THEM. FROM YEARS OF EXPERIENCE I FIND RUNNING AT CLOSER TO MAX ON THE SIDEWALL RATHER THAN THE DOOR JAMB IS THE BEST WAY TO RUN TIRES. AND I ALWAYS BUY PERFORMANCE TIRES.


#11

Here’s what DOT/NHTSA has to say (short version - use the door jamb value, measure it with the tire cold).
http://www.nhtsa.dot.gov/cars/rules/TireSafety/ridesonit/brochure.html


#12

FOR MY WINTER TIRES WITH 44 MAX PSI SIDEWALL RATING I USE 40 PSI. WORKS FOR ME AND WIFEY AND DAUGHTER.


#13

Thanks Tex, you are totally right.


#14

My thought is if the tire is designed to be run at 44 psi

No, the tyre is designed to run at 44 [b] or less [/b]  Using an amount other than that specified by by the guys and gals who designed the car and tested it on a test track under all kinds of conditions with that size tyre is foolish.  We all need more traction during emergencies.  Hopefully we will not have an emergency, but if your tyres or over (or under) inflated in an emergency situation it could be very very bad.  

 The tyre manufacturer has not tested those tyres on every possible car, nor is it likely that all cars using that same size tyre will need the same inflation.

#15

Maybe I have it backwards, I would go for the 44 psi knowing that gas mileage would be better, but the ride and traction would be worse.

WO…WO…WO…

The ride and handling isn’t going to be a little worse…it could be down right unsafe. Traction/handling/ride comfort will all be effected.

Now lets talk about gas mileage…Any money you save on gas (which is MINIMUM) it’ll be lost because you’ll be replacing the tires at 20k instead of 50k.


#16

#17

LOL