tire pressure question-what to believe

[Paul_]

alrighty i'm stickieing this even tho i'm asking the question but it will help others for sure as it can be a safety issue. what is the proper school of thought on how much pressure to put in your tires.

i hear some people say you are supposed to go with the auto manufactureres reccomended pressure, and then i hear that you are supposed to go with the tire makers max pressure. what is the right way to go? i would assume that the car makers reccomendation would be based on the tires that they mount stock, but i don't know.

[Ifixyawata]

As long as you're using one of the sizes listed on the car, use the manufacturer's tire pressure. Max pressure is never good and will surely lead to uneven wear down the center of the tread.

[DuceAnAHalf]

i run 40 PSI in my 235/60 r 16 and they still have a little bulge from the weighti think ford says 32 or 35, Kumho says max 44 and the rim says max. 60

[Grand Marquis GT]

I usually run 35 or 32 as a rule...

[Lincolnmania]

i run my tires at maximum inflation pressure with excellent resuts
the tires on my towncar are set at 44 psi
scott

[85crownHPP]

tire pressure is specific to the car.. look on your door jamb for pressure with your stock size tires, if you have different size, all bet are off!

[bruno]

Door jam for stock tires. Max for any other tire that is not the same MAX PSI on the stock tire or if you change it around completely

What happens when you over inflate a tire.... nothing on your luxary car. The suspenstion is smooth enough to handle any discrepencies that might show up on a smaller car, say... a civic, and you wouldnt hurt anything on your car, cept tire wear.

[DuceAnAHalf]

the more pressure in a tire the better it is for handeling but the ride quality goes down, but do not go over the max pressure

[Mercracer]

Too high with no load will cause you to ride more on the center tread which will wear out the center quicker and hurt handling and traction.

[DuceAnAHalf]

even with 40PSI the tires still squat, i always have 2-300 lBs. of stuff in the trunk

[Fairmont Kevin]

The factory pressures are a compromise between a smooth ride, tire wear and performance. I'm betting smooth ride was the # 1 priority.

Here's something important: If your factory recommendations are different between front and rear, as you experiment with pressures to see what fits your priorities, keep the difference between front and rear proportional to the original recommendation.

[Blaze86Vic]

I run 33 front and 30 rear. I'm happy with this setup but you have to adjust your pressure depending on how it rides, and how it is wearing. If it’s wearing down the center faster lower the pressure. Always run the front a little high so that the center has a chance to wear down some.

I used to run 36 front and 28 rear with those cheap Cooper Cobra tires. And they wore even and good, but the ride was still rough. Once I got a new set of Cooper Lifeliner STE T-rated tires it was like driving a new car, all smooth and better response, I also had to raise the pressure up in the rear and lower in the front.

Handling and ride effects of pressure. More pressure makes for a rougher ride and less traction, but it rolls easier so it's better on mileage. Less pressure makes for smoother ride and better traction, but the better traction is only to a point, after that point you will get more launch traction but your turning traction will go away because of tire roll.

Also running low will flex the sidewall too much and cause the sidewall to fatigue pre-maturely. What this means is that after 10,000miles of low pressure, to get the tire to not look like it's squatting you have to run the pressure too high.

Make the pressure what you want to make it, it's personal preference. There are just four basic rules.
4 RULES:
1: DON'T GO ABOVE THE MAX
2: DON'T RUN THEM FLAT
3: Adjust depending on tire wear
4: Adjust depending on ride quality