44 psi tires

[jdham137]

For the guys on the list that run 44 psi rated tires, do any of you run them higher than 44 psi? Do you feel safe doing so?

John

[JanGeo]

Some are going higher - mine were at 40 psi and when the weather got warmer they were up to 45psi a month AFTER I had set them to 40 so air seems to have LEAKED INTO THEM - just a note that apparently the higher the pressure the more you have to watch them. That or my digital gauge is acting up from too much pressure - it's rated up to 50 psi but . . . I don't feel that comfortable running too high as it adds more stress to the tire and could result in a really loud blowout instead of a puncture.

[bbgobie]

Originally Posted by JanGeo

Some are going higher - mine were at 40 psi and when the weather got warmer they were up to 45psi a month AFTER I had set them to 40 so air seems to have LEAKED INTO THEM - just a note that apparently the higher the pressure the more you have to watch them. That or my digital gauge is acting up from too much pressure - it's rated up to 50 psi but . . . I don't feel that comfortable running too high as it adds more stress to the tire and could result in a really loud blowout instead of a puncture.

Most materials expand when heated. So going from cold weather to hot weather can increase ur PSI. Also if you first checked after a cold night, and than next time you drove around heating up your tires and checked that can increase PSI.

[JanGeo]

Yeah I know that but driving at 25mph for a mile is not going to get them that warm on a 60 degree day and that was when I found the pressure at 45psi and usually I inflate during the day - no point in doing it when it's cold outside. Be really funny if they warm up and the pressure changes a lot in the first few miles of driving - could explain some of the mileage variations on short vs longer trips.

[Gary Palmer]

I am running 55 psi in tires that are rated at 36. I have been running them for about 8 months, without any particular problems. The only problems I have encountered is they ride rougher and they wear down the middle more than the sides. As far as road contact, after the first couple of months, the tires are worn to suit the amount of pressure, so the road contact does not seem to be as much an issue.

I realize people are afraid of having a bigger issue if a tire blows out, but from what I've seen I think your less likely to have a blowout because the tire sidewalls are so stiff that the tires don't really flex, hense the rough ride. If they develop a leak which lets the tires get low, so that they heat up and blow out, then they would have done the same thing at whatever tire pressures you had them at.

As far as safety is concerned, I am not saying everyone should run 55, but I haven't had any problems that I have seen and I wouldn't be concerned about doing so, from a safety standpoint.

[brucepick]

I read that tire pressure goes up~1 psi per ten degrees F increase iin outdoor temperature. Checking in cold mornings vs. warmer afternoons pretty much bears this out.

Further, I live about a mile from my preferred air pump. I take the interstate to get there (I live right by an exit). I've found that the tires will gain a pound or two just from that short drive at 50-55 mph or so.

[zpiloto]

Originally Posted by Gary Palmer

I am running 55 psi in tires that are rated at 36. I have been running them for about 8 months, without any particular problems. The only problems I have encountered is they ride rougher and they wear down the middle more than the sides.

What kind of tires are you running? Interesting. You're the only one I heard mention that the centers are wearing more than the rest.

[MorningGaser]

I run 55 psi...the side wall limit is 44 for my tires...I have a 2,200 lbs Yaris, a light car, that I never drive fast with, so I don't worry about blow outs or anything like that.

After 4,300 miles no issues, and they are wearing like normal.

[brucepick]

Originally Posted by zpiloto

What kind of tires are you running? Interesting. You're the only one I heard mention that the centers are wearing more than the rest.

Nah. Old story. Way way back when I was a young driver there were pics showing various kinds of bad tire wear (including alignment problems etc). Overinflation = more wear in the middle. Underinflation = more wear on the outside.

What they didn't tell you then was that more air pressure = higher FE.

[psyshack]

I run 50 psi in my tires rates for 44. No problems at all. The Accord and Civic both handel better and road noise is lower. They do ride firmer.

[zpiloto]

Originally Posted by brucepick

Nah. Old story. Way way back when I was a young driver there were pics showing various kinds of bad tire wear (including alignment problems etc). Overinflation = more wear in the middle. Underinflation = more wear on the outside.

What they didn't tell you then was that more air pressure = higher FE.

Well I think if Gary says that his tires are wearing in the middle then there probably wearing in the middle. I just want to know what kind of tire he's running because as most folks have alluded to they have no abnormal wear from elevated pressures.

[basjoos]

I have 50,000 miles on my 44psi rated Michilin Harmony tires which I keep at 55 to 60psi. They handle better (less likely to squeal through a hard curve) and have normal treadwear patterns.

[brucepick]

Just bear in mind that when you still have 60-80 % of your tread remaining it's not that easy to see visually if there's more wear in the center. But when it wears down and the center has 2/32" and the outside has 4/32" you can easily see the difference, and its kinda too late.

Years ago I grabbed a tread depth gauge. Just a couple dollars I think, but you might need to go to a real parts store, not a big box store. Or you can use a penny etc., just compare carefully between the different grooves.

[omgwtfbyobbq]

Does anyone know where I could find info on how tire pressure increase w/ heat/speed? That'd settle things, since we could roughly guessimate the pressure needed for the energy in a stock tire at ~55mph to equal the pressure in a tire at the manufacturer's specs, i.e. max pressure/speed/heat.

[psyshack]

Tires dont wear like they use to over all unless under inflated. The bias ply corded tires of years past would wear the center real bad when so called over inflated. Steel belted radials handel the psi diff. And with the over all shorter side wall heights its a diff. game now days.

psy

[Gary Palmer]

Zpiloto: The tires I am running on are Michelins. I am running them on the ultra thin side, at the moment, so I think that is the primary reason I can see more wear on the middle than the edges. I know I am almost down to no tread in the middle and the outside is probably a 1/16 or less.

I switched them from 35psi to 55psi, last year. I was so impressed by how much farther the car rolled when I was coasting out of gear, that I left them at 55. I haven't tried running them at anything less, even though I suspect I could run them lower, to some point and get pretty much the same affect.

The tread wear differential, with the wear in the center of the tread is very acceptable, given that I used to get at least that much treadwear on the edges, anyway. I just haven't been inclined to lower them any, since I drive the car, primarily and it helps enough with mileage, IMO, that I just haven't been inclined to fiddle with anything any lower.

[JanGeo]

Well you are on the high side of pressure but the 44psi max is for COLD pressure and they can get hot and go higher. Also having tread on the sides is better because that is where the water needs more tread to get up from under the tire and where you need tread for cornering. Going straight should be ok with slick centers and when stopping the front tires get more weight transferrred to them so that higher pressure helps them from squeeling which is probably because the recommended pressure is fine until you do have to brake hard and the weight load increases on the tires changing the contact patch and looses traction. At any rate of wear higher pressure should make them last longer but when they are worn out they ARE worn out and you have to get new tires.

[VetteOwner]

the psi in tires increases when they get warm (they get warm from friction between the tire and road, and sun but thats only if they've been sitting in it all day) because of the air inside heats up and expands...

but yea i have noticed that my cars tires even tho thier rated at 35 i have them at 40 or so cold that i see no different wear on the tires.(thier already bald so i might bump it up more to see what happens)

[JanGeo]

Just watch for little buldges in the side walls - cards starting to break inside - could result in a very loud bang!

[Erdrick]

Glad that this topic came up. I have a question about increased pressures. I personally have my car bumped up from a suggested 32 to a more FE-friendly 55. The car handles MUCH better. I didn't expect much of a difference, but it is like I upgraded to better tires as the car now tracks with much more precision. The ride was VERY BAD to begin with, so I haven't even noticed a harsher ride. The fuel economy is looking to have gotten better. I just changed my route (from all city to all rural), so I will have to wait a while longer to see what the real FE effects were.

So, here is my question. Gary has shown that some tires CAN get abnormal wear from overinflation. Is it also possible that the car's suspension also be negatively affected? The tires are directly transferring more vibration from the road through the suspension into the car. Should we expect to have to replace suspension parts earlier than usual if we are running high psi?

[omgwtfbyobbq]

I think it's very unlikely w/ the suspension assuming you're at 55mph compared to 65mph+. The tires will be more susceptible to damage from larger obstacles like bit pot holes or rocks, but as long as your commute is reasonably smooth you should be fine.

[Erdrick]

I personally drive at 55mph, but the person who I am asking for usually does 75-80mph. They also encounter some pretty bad highways. Michigan roads are a... well, a *****. This person also carries anywhere from 100-500 lbs plus on a daily basis due to their line of work. They drive a GMC Envoy XL.

[MnFocus]

If the load range of the tire is correct for the weight of the vehicle-with a Suburban I'd say battle tank - there should be no harm in increased tire pressures . If disgression is used , that is .Try 80% of max sidewall first then bump it up 2-3 psi a tank fill to owner satisfaction or within 20-30 % *over* max sidewall . This is my personal way of testing and not a recommendation to *just do it* without owner attention .

[MnFocus]

Sorry for the tire rack recommendation - I just find the site useful for a lot of info about rolling stock Not just shopping . Pertinant info follows :PSI & Temp fluctuation

Load rating

Load Index

[diamondlarry]

I have run 60 psi for ~10K miles in the tires that were on my Saturn with no visible signs of uneven wear. My son's car has 55-60 psi in the same type of tires with no odd wear patterns either. They both are Goodyear Assurance Comfortread.

[slurp812]

Before I got on this forum, I ran mine anywhere from 35-37 for thousands of miles, no abnormal wear. The car says to use 29. Now however I have them at 39 psi. we'll see how they wear after a year or so...

[Snax]

I think it's safe to say both literally and figuratively, your mileage may vary.

More durable tires with stronger belts are likely to wear more evenly. I'd wager that the really cheap ones don't.

[repete86]

My tires are only rated for 35 psi, but I'm running 50 in front and 60 in the back.

[kickflipjr]

I did have a tire warp on me. If your tries are new and good quality then I see no problems running 50-55psi.

Check out this thread to see the tire damages.

http://www.gassavers.org/showthread....ht=warped+tire

[caprice]

At higher speeds, a car with overinflated tires, will more likely handle skittish at higher speeds. Just something to watch out for.