What tire pressure?

[mikenmar]

What tire pressure are you all using?

 

I think the manual says 32-33 psi, but wouldn't you use a bit more if you were willing to sacrifice a little comfort for the extra mileage?

Edited May 19, 2010 by mikenmar

[rfruth]

~37 all around here, no problems that I know of

[2010 Sport Blue SEL]

What tire pressure are you all using?

 

I think the manual says 32-33 psi, but wouldn't you use a bit more if you were willing to sacrifice a little comfort for the extra mileage?

You've opened a can of worms here. My guess is there are going to be dozens of different opinions on this subject. Personally, I inflate to 33 psi, as stated on the door panel and in the owner's guide. I keep pretty close watch and check frequently. I have a thermometer in my garage and a small compressor, when the ambient temp changes I check and fill or deflate as needed. I use the average daily high temp as a guide and always check when the tires are cold. Here in Minnesota, one needs to keep a close watch winter to spring and fall to winter.

[xmech2k]

I think long term, running such a high pressure, you'll get uneven premature tire wear. Will it be worth it when it comes time (early?) to replace them?

[rfruth]

I think long term, running such a high pressure, you'll get uneven premature tire wear. Will it be worth it when it comes time (early?) to replace them?

 

 

Is my ~37 the high pressure x (the last few cars I drove I ran a few more PSI than recommended & had no uneven or premature wear but will my Fusion be the same) ?

 

 

[Rodeo]

I am running 35-36 psi in my Milan and that's a few pouinds above the recommended 33 on the door sil. I ran the same tire pressure on my Ford Escape in Continental tires and they wore like iron, getting over 60K on them before I replaced them (just becuase I could, not because they need to be.) They still had lots of legal thread left and the wear was even. I think a few pounds over prolongs tire life, not hinders it.

[oldschool1962]

It's always been my understanding that........if you run just under the max pressure as stated on the tire you shouldn't have issues with abnormal wear or safety concerns. Just remember not to exceed the maximum pressure and take into consideration the 1-3lb increase in pressure as the tires heat up. To get a good gauge of this you should check pressure after you have driven for a while. You can always reduce to set it under that max stated pressure if it exceeds it. We have typically run the higher side of the scale with no issues...... at least what I can recall over the last 40 years.

Edited May 19, 2010 by oldschool1962

[Rodeo]

It's always been my understanding that........if you run with the pressure as stated on the tire you shouldn't have issues with abnormal wear or safety concerns. Just remember not to exceed the maximum pressure and take into consideration the 1-3lb increase in pressure as the tires heat up. To get a good gauge of this you should check pressure after you have driven for a while. You can always reduce, as needed, to stay under the max stated pressure. We have typically run the higher side of the scale with no issues...... that I can recall over the last 40 years.

Tires don't state "running pressure" they state the "maximum pressure" and are rated for their speed rating, knowing they will heat up and increase in pressure as you drive. The maximum pressure is not the recommended running pressure and that info is typically specified by the car manufacturer and in the case of Ford, put right on the door sill in plain view. The recommended pressure assumes the tires will heat up and increase on their own, so no need to compensate and deflate for heated expansion pressure. it is this fluctuation in pressure that causes more wear then had the tires remained constant and that's one reason why inflating with Nitrogen is so beneficial. Nitrogen filled tires will reduce heat and keep pressure constant, prolonging tire wear and lessening chances of blow outs too. Not to mention an inprovement in fuel mileage as well. Tires should never be adjusted hot or warm even.

Edited May 19, 2010 by Rodeo

[rpreuss]

Interesting discussion.

 

Everyone (as expected) is saying "follow the door sticker", "+ X lbs.", etc.

 

Try this the next time you are with a bunch of your "car" friends...

 

Everyone get out your tire gauges and all measure the pressure in the same tire. (NOTE - Do not do this AFTER you have your beers... you may loose too much air between each reading). Now compare the readings. I will bet that you will find quite a range of readings, +/- a couple of PSI.

 

For the most part, these are all cheap gauges with quite a bit of variations. So, keep that in mind when you are adjusting your tires to your own "preferred" pressure.

 

Now, go have your beers. :beerchug:

[chriscard25]

Tires don't state "running pressure" they state the "maximum pressure" and are rated for their speed rating, knowing they will heat up and increase in pressure as you drive. The maximum pressure is not the recommended running pressure and that info is typically specified by the car manufacturer and in the case of Ford, put right on the door sill in plain view. The recommended pressure assumes the tires will heat up and increase on their own, so no need to compensate and deflate for heated expansion pressure. it is this fluctuation in pressure that causes more wear then had the tires remained constant and that's one reason why inflating with Nitrogen is so beneficial. Nitrogen filled tires will reduce heat and keep pressure constant, prolonging tire wear and lessening chances of blow outs too. Not to mention an inprovement in fuel mileage as well. Tires should never be adjusted hot or warm even.

 

 

I use 78% Nitrogen in mine with great results.

Edited May 19, 2010 by chriscard25

[akirby]

I use 78% Nitrogen in mine with great results.

 

Hey - that's MY line! Actually I usually say that it's a 78% Nitrogen, 21% oxygen blend............

 

 

The mfr recommended pressure is perfectly fine but never go below it. It's ok to go above it by a few pounds based on personal preference. I like to run 35-36 just to have a cushion when the pressure drops. The differences in mileage and handling are there but negligible.

 

Some people run 40 psi or higher but IMO that's too high unless you're autocrossing. You should never come close to the MAX pressure on the sidewall of the tire under any circumstance - it's not necessary and it can be dangerous. And all tire pressures are given as cold readings and take into account the pressure increase after driving. Always check and fill your tires when they're cold.

[sullied]

it is this fluctuation in pressure that causes more wear then had the tires remained constant and that's one reason why inflating with Nitrogen is so beneficial. Nitrogen filled tires will reduce heat and keep pressure constant, prolonging tire wear and lessening chances of blow outs too.

The ideal gas law would tend to agree with you. All gases near standard temperature and pressure follow the law the same way...Nitrogen is no different. As temperature increases, pressure increases regardless of what type of gas is filling your tires. It can help to reduce the amount of water vapor in your tires since compressed air has some water vapor, but it doesn't make a whole lot of difference really. The only real benefit is that it inerts the air...but I don't think many people have open flames near their tires very often.

 

Supposedly it will help reduce pressure loss from the molecules diffusing through the rubber...but I'm pretty skeptical on that.

 

Save your money and check your pressure often in my opinion.

[akirby]

it is this fluctuation in pressure that causes more wear then had the tires remained constant and that's one reason why inflating with Nitrogen is so beneficial. Nitrogen filled tires will reduce heat and keep pressure constant, prolonging tire wear and lessening chances of blow outs too.

 

Any fluctuation would occur within the first mile or two - after that it's constant. Nitrogen filled tires do not reduce heat. Where do you get these fairy tales?

 

There is some research to suggest nitrogen leaks out more slowly but that only matters if you don't check your tire pressures once every month or so.

The main benefit is that it doesn't contain water vapor which can lead to corrosion especially in truck tires that are re-treaded many times. And it's inert for high temp applications like aircraft tires.

[Waldo]

It's always been my understanding that........if you run just under the max pressure as stated on the tire you shouldn't have issues with abnormal wear or safety concerns.

 

Your understanding is a mis-understanding. The max pressure on the side of the tire has absolutely no relationa at all to the wear and grip characteristics of the tire. By running pressures significantly (more than ~5psi) higher than the one printed on the door sticker, you will wear the tires abnormally and will not have as much grip, especially under braking.

[xmech2k]

I agree with Waldo. Think of those tire commercials where they show the tire from underneath running over some clear material. You get to see what part of the tire really meets the road. The part on the ground flattens a bit. If the pressure is too high, you would get less contact area, since the tire doesn't flatten as much, and is somewhat ballooned, causing the center of the tread to contact more than the edges, which is where the uneven wear thing comes in as well. Less contact area=less traction. Hence the attention to tire pressures in racing. More pressure=less resistance=more speed, but that also means less traction, so they have to find just the right balance between speed and traction.

 

I'm suprised people have done this for 60k+ miles and didn't get the uneven tire wear. Never done it myself, so I'm only going on what the 'experts' tell us. Maybe it's a conspiracy, and the tires would be fine at 100 psi, but they'll wear faster at the lower pressures so we'll have to buy more...

[TonyPSchaefer]

I have run high pressure in my vehicles for years. I no longer give out specifics due to the backlash and panicked replies I get. I have never had uneven wear nor have I ever experienced a "loss in traction." The ride is stiffer, yes. There is a very noticeable increase in mileage. The exact same results have been anecdotally experienced by many others. http://www.greenhybrid.com/discuss/f12/tire-pressure-does-effect-mpg-how-much-too-much-1297/

 

Some have worked to prove these things through experiments. http://www.nhtsa.gov/cars/rules/rulings/tirepressure/LTPW3.html

 

In the end, I've always held to this one thing: we're responsible adults who have spent good money for something. Whether or not we choose to adhere strictly to manufacturer suggestions or vary is entirely up to us. Whether we choose to listen to advice from others regarding our things is entirely up to us. However, if you choose to vary from the manufacturer's suggestions and the advice from others, be prepared to hear "I told you so."

[akirby]

My issue is that the tire mfrs and vehicle mfrs have good reasons for not recommending higher pressures.

 

With CAFE you would think the vehicle mfrs would go out of their way for a few extra MPG even if it meant a stiffer ride. They don't.

 

Tire mfrs don't have to worry about CAFE - they only have to worry about safety. If the company that makes the tires says not to run them above 44 lbs (e.g.) then why would you assume that you know more than they do based strictly on ANECDOTAL evidence?

 

I'm sure there are people who have played Russian roulette dozens of times and are still alive. Does that mean it's a good idea?

[ace43]

I run my tires at 30 psi and am thinking about going lower than that just to get a smoother ride. I'm still getting mpg between 40 and 43 with that setup, although I might do better if I pumped them up a bit. For years I had a Ford pickup that never had anything in the bed, so I ran the tires at 25 front and 20 back. It made a big difference in ride. I'm sure that tire wear in such a case was inferior, but I was willing to put up with that for the better ride. When I took delivery on my FFH, the tires were at 35 front and rear. I like the ride of the FFH, but it can be a bit jarring over tar strips, etc. Lowering the pressures to 30 front and back made a difference. I'm not recommending such a procedure unless ride is more important than tire wear.

[Rodeo]

I run my tires at 30 psi and am thinking about going lower than that just to get a smoother ride. I'm still getting mpg between 40 and 43 with that setup, although I might do better if I pumped them up a bit. For years I had a Ford pickup that never had anything in the bed, so I ran the tires at 25 front and 20 back. It made a big difference in ride. I'm sure that tire wear in such a case was inferior, but I was willing to put up with that for the better ride. When I took delivery on my FFH, the tires were at 35 front and rear. I like the ride of the FFH, but it can be a bit jarring over tar strips, etc. Lowering the pressures to 30 front and back made a difference. I'm not recommending such a procedure unless ride is more important than tire wear.

30 psi OK but 25 and 20 psi especially is going to affect handling without question. That could even be dangerous if you ever need to maneuver in an emergency.

[DaveM]

I run my tires at 30 psi and am thinking about going lower than that just to get a smoother ride. I'm still getting mpg between 40 and 43 with that setup, although I might do better if I pumped them up a bit. For years I had a Ford pickup that never had anything in the bed, so I ran the tires at 25 front and 20 back. It made a big difference in ride. I'm sure that tire wear in such a case was inferior, but I was willing to put up with that for the better ride. When I took delivery on my FFH, the tires were at 35 front and rear. I like the ride of the FFH, but it can be a bit jarring over tar strips, etc. Lowering the pressures to 30 front and back made a difference. I'm not recommending such a procedure unless ride is more important than tire wear.

 

That was the main reason Ford and Firestone got into trouble a few years ago. Ford in order to get a better ride had the tire pressures on the Explorer about 4 to 6 lbs below what they should have been causing them to heat up on the highway till they blew causing crashes and death. Is a little bit smoother ride worth your life. Me, NO.

[2010 Sport Blue SEL]

If one chooses to run their tires significantly above or below the manufacturers recommendation you run the risk of not having any recourse if the tires contributed to a collision, rollover or death. After the Firestone/Explorer events, if the tires played a part in the crash, you have to think that Ford, or any other auto maker would check the tires and use that info in court. It's not worth the risk to me for a very minor increase in mpg's.

[lolder]

Fall weather and lowering temperatures make this the time to check your tire pressures. Mine were uniformly down 5 psi (to 31) in still-pretty-warm S. Florida.

[WScottCross]

I think long term, running such a high pressure, you'll get uneven premature tire wear. Will it be worth it when it comes time (early?) to replace them?

 

I disagree on the uneven wear. I ran my FEH on the original tires at 40 PSI for 94,000 miles before I replaced them and they were still not down to the wear indicators. I got the MOST even wear I have ever seen on those tires. Now when it comes to ride comfort, that is another story altogether! It does make the ride a bit harsher, especially in the Escape. I pumped my wife's FFH tires up to 40 and it still rides pretty smooth, so we're leaving them there.

[Fuze-ion]

I have been running 37-38, and I don't notice any issues. The ride is still comfortable and the tires respond fine. It think it is a happy medium.

[rfruth]

The convenience factor, the car handles better (& gets better MPG) is why i like 37 PSI

Edited November 3, 2010 by rfruth