Today a light came on while driving. Normally it indicates a tire pressure problem. Checked each tire when I got home. Three where at 42# and one was at 44#. I thought that was kind of high, I thought tires where normally around 32#. Checked the tires and they say max of 44#. They are Big O Euro Traveler 215/55R17 tires. Do you think the pressure is too high? If not, maybe the light has something to do with my battery problems from yesterday. Thanks for your thoughts.

ignore max pressure rating on the tire, look at the label on your car (usually on driver's door frame)

Tires should be inflated to what it says on a sticker where you open the driver side door. 32psi doesn't mean anything anymore. Tires are usually marked only by max. psi.

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Grateful11

There has been a trend the last several years to increase tire pressure, as it also increases milage. The tire makers have been making tires that run and perform better at higher pressures than in prior years... so, if you've got an older car, the good old door sticker that came with it when it was manufactured may no longer be applicable when you get a new set of tires. Check with a good tire guy to get a handle on what's right for your car/tire combination.


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Lazy,

If I remember correctly and hopefully others will confirm, check your ties when the engine is cold. Meaning, not after you've driven for a while. I'm pretty sure it's because the air inside them expands from the heat. So, checking them when warm will give you a false reading. As Grateful said, they're supposed to be filled to the pressure dictated by the sticker on the inside of the driver's door.

Here's a nifty site for more details:

[www.wikihow.com]

Robert

Measuring tire pressure immediately after driving on them (for more than a very short time), will give you "inflated" false readings. Most accurate way to measure TP is, for most vehicles, first thing in the morning when the tires are cold. Sticker on door post is a good starting point. Check the Owner's Manual for more detailed information. The load the vehicle is carrying affects what the proper pressure the tires should be inflated to.

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Buzz
There has been a trend the last several years to increase tire pressure, as it also increases milage. The tire makers have been making tires that run and perform better at higher pressures than in prior years... so, if you've got an older car, the good old door sticker that came with it when it was manufactured may no longer be applicable when you get a new set of tires. Check with a good tire guy to get a handle on what's right for your car/tire combination.


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There's a lot of other factors in play. Just because a tire can be inflated to a higher pressure doesn't mean they should be nor that it will get better milage. Over inflating a tire will cause premature wear which will most likely negate the potential fuel savings.

Also, where did you get that info? None of the tire sites (eg Tire Rack) say anything about that.

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Maximum tire pressures are usually reserved for load carrying.

Heavily loading tires at normal pressures usually changes the contact patch, putting more weight on the outer edges of the tire. Inflating not to exceed MAX pressure serves to flatten the contact patch so that the full width of the tire tread contact the ground evenly.

This should assure better traction and braking, even tread wear, and prevent tire and rim damage.

If you're not carrying a heavy load, then it's most likely not a good idea to run at MAX pressure as the contact patch will tend to be narrower, reducing tire performance.

Again, check the manufactures specs for proper pressure. That could change when different brands of tires are used, but unless you're pushing a performance envelope, it really won't make much difference.

My car is an '02, and the OEM pressure is supposed to be 32psi. I usually inflate them to 38psi.

Your mileage may vary.

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testcase
...Check the Owner's Manual for more detailed information. The load the vehicle is carrying affects what the proper pressure the tires should be inflated to.

he doesn't like to read long manuals just to learn simple things

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M A V I C

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Buzz
There has been a trend the last several years to increase tire pressure, as it also increases milage. The tire makers have been making tires that run and perform better at higher pressures than in prior years... so, if you've got an older car, the good old door sticker that came with it when it was manufactured may no longer be applicable when you get a new set of tires. Check with a good tire guy to get a handle on what's right for your car/tire combination.


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There's a lot of other factors in play. Just because a tire can be inflated to a higher pressure doesn't mean they should be nor that it will get better milage. Over inflating a tire will cause premature wear which will most likely negate the potential fuel savings.

Also, where did you get that info? None of the tire sites (eg Tire Rack) say anything about that.

Call your guy at Tire Rack... it's not an exact science, it's still load rating vs. actual load vs. tire's specs. Just sayin' the last several years the tire makers, in conjunction w/ the car makers, have been upping the pressure and tire specs to help up the milage, and in many cases the current best practice for a new set of tires may be a few #'s more psi than is printed on the door jam... hence, I'd rely on the good, well-informed, tire guy when buying a new set of tires for an older car, rather than the older car's old door jam sticker. OTOH, if you get a new car before the original tires wear out, it's a moot point. Another point is the speed and handling rating differences for different tires of the same size; there may well be a pretty big difference in applicable pressure, and just because your hot rod came w/ V rated tires, you may want to replace them w/ H or S rated tires and drive like an old fuddy duddy for the rest of the car's life.

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Low profile tires typically require more pressure then 70 and 75 series tires from years ago. Different models of tires also require different pressures.

Remember the Firestone/Explorer blow outs? Ford specified 28 PSI and the tires would get too hot and fail. The same tires on thousands of Chevy Trailblazers had no problems, Chevy specified 32 PSI.

More pressure typically can help in milage, cornering grip and response, make for a rougher ride.

My sons Scion xD came from the dealer with 17" wheels and I think 225/45-17's and his car has two stickers on
the door jamb, one for the stock size from the factory and one for the Pirelli P-Zero's that were put on state where
it came into the country. So you have watch out for these type things. I know a guy that runs 45 psi in his Highlander
because he says it boosts his mileage, yeah it probably does but it just about has to ride like a rock. I bet he wears
the center of his tread out prematurely.

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Grateful11

Thank you for all of the info. I'll check the car's suggested pressure rating. I'm pretty sure it's in the 30's. Thank you.

My alignment guy that I trusted back when always said that the best, most even wear on passenger vehicles came with an inflation pressure of 35 psi. I've been using it ever since, and tire guys always remark about how even the wear is on my tires, no matter how old they are. No science, just good advice.

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What it is, man, a low-down and funky feelin'

Again, it depends on the tire and size. Like on a 19" ultra low profile Potenza RE11 performance tire, anything under 42 psi would be considered under inflated. They work great at 50 psi.

Large truck tires, like on uHauls and such run at 100psi or more

It's safe to run tires at their max pressure as stated on the side wall, if the car rides too rough, back it down a little

The TIPS on my Ford is quite sensitive and comes on if pressure varies only 2-3 psi from the set value. Your manual should tell what the TIPS setting is for your vehicle and that should help you decide if you are high or low.

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Dick Moore
My alignment guy that I trusted back when always said that the best, most even wear on passenger vehicles came with an inflation pressure of 35 psi. I've been using it ever since, and tire guys always remark about how even the wear is on my tires, no matter how old they are. No science, just good advice.

That might have worked on your car but that is bogus advice if applied universally. Small changes in tire pressures have a very large effect on performance and longevity. The correct tire pressure is defined by the relationship between car weight, fore-aft weight distribution and contact patch size (which changes with different tire and wheel sizes). The car manufacturers specifications (or road testing) are the only proper source of that information unless you are using a tire/wheel combo that they don't give a recommendation for.

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I know it sounds stupid, but make sure your gauge is working properly, and never rely on what the air pump at the gas station says. I've gone to 3 different gas stations in the scope of a few minutes and received very different readings each time...