Tire Pressure

[Almost There]

How hard do you keep your tires for general driving?

With almost a grand into new tires I want to make them last as long as possible.

I'm getting conflicting opinions.

In order of importance: 1. good handling, 2. long wear 3.comfortable ride.

Do you keep them near max pressure that's found on the sidewall, what's on the sticker on the door jamb?

What say y'all!

 

[Optimistic Paranoid]

An over-inflated tire will wear out the center treads.  An underinflated tire will wear the edge treads, plus will tend to run hotter than a properly inflated tire.  Check out http://www.ehow.com/how_6948382_chalk-tires.html
for a simple test you can run on your tires.

Regards
John

 

[Almost There]

An over-inflated tire will wear out the center treads.  An underinflated tire will wear the edge treads, plus will tend to run hotter than a properly inflated tire.  Check out http://www.ehow.com/how_6948382_chalk-tires.html
for a simple test you can run on your tires.

Regards
John

While looking at that link, for which I thank you, I found yet another Ehow on tire pressure.

http://www.ehow.com/how_6825073_calculate-correct-tire-pressure.html

Wonder which one is right or if they'll both end up with the same amount of air!!

 

[WheelEstate USA]

I sorta go with the second version. These tires call for 60 max, but we're not running max weight in our 1 ton either. We seem to do well with about 55 lbs and it rolls pretty firm still.

Unless you know your weight chalking might give you a better idea of where you stand.

 

[Optimistic Paranoid]

I don't think much of the second "system".  I makes no allowance for how much weight the tire is supporting.  An empty pick-up truck needs less air in the back tires than one hauling a full load does.

Ultimately, you want your tires to wear evenly from edge to edge.  You could get one of those tire depth gauges and check across the tread every thousand miles or so, adjusting the air pressure up or down as needed to get even wear.  Which is what the chalk trick is supposed to be a shortcut to achieving.

Regards
John 

 

[Bdog1]

If everything is stock/original, it's probably a good bet to go with the door plaque.

 

[Reducto]

I try to get it right at what the door plaque says. The vehicle was designed with that in mind.

 

[Almost There]

If everything is stock/original, it's probably a good bet to go with the door plaque.

Therein lies the problem, it's not stock.

I have the fiberglass high top on already and over the next few months it's getting a full camping interior complete with house battery system, kitchen unit, etc. etc. It won't come near to maxing out the weight but still!

I think for right now I'll snag a piece of sidewalk chalk from a friends' teen and try the chalk method unless and until I have a better idea.

 

[LeeRevell]

For my minivan, the tires state a MAX of 35PSI, so that is what I run it at. I do tend to keep it loaded, so I get good tire life with this. But when I take it to SuperLube, they consistently adjust them to 32PSI, making me have to reair them back to 35PSI. Works for me. Been lazy about the tires on the E150 - need to check them.

 

[wayne49]

I know that race cars use temperature across the tread to evaluate pressure, alignment and compound issues. Don't know if a person could use a infrared temp gun to monitor a street tire in a similar way.
http://www.elephantracing.com/techtopic/tiretemp.htm

Guy

Thanks for the link.

One could use infrared gun, most racers use guns now, rather than probes. The issue is street tires will not have the wide variation in temps as racing tires.

Racing tires are designed to work at higher temps and to warm up quickly. They also wear out quickly. 1# makes a big difference with a race tire.

Street tires not so much. Designed to last much longer. The temp variations across the tread would be much smaller than on a racing tire.

You can lay your palm across a "hot" street tire to feel the temp variation. Try that on a hot race tire and your palm will have burns.

 

[MikeRuth]

On my Ford E-150 I had originally thought that running a little less since it was empty would be OK.

what I found was not so much a problem with uneven wear but poor handling. Steering was a bit soft and not as responsive.

I went back to running the pressure stated on the door tag. 55 frt 80 rear. Definitely tracks truer and responds to steering input better.

I'm sure I could get away with lowering the rear to 55 as well since I'm not carrying but a couple hundred pounds more than empty but that means added rolling resistance.

And on another note I have read several times from different articles that lower tire pressure is a bad deal in the wet! One of the videos I saw was made by a tire manufacture that videoed the tire through glass as it passed over in the wet. It was a remarkable difference when the pressure was to low as it would not pass the water through the tread as it should have, therefore causing early hydroplaning.

For those thinking they could get by with temp measurement like a race car...I think not as one we don't really have a spec for that temp, along with the outside variable air temp and how hard you really are on the tire. Consider it could be a cooler than normal day versus a hot day versus the speed and road conditions.

An easy drive down a mountain road versus a hard drive down the same road could certainly result in widely varying temp.
And if you are going to try that, you need to get those temps as quickly as possible after stopping the vehicle otherwise your temps are going to equalize and be useless.

 

[Almost There]

On my Ford E-150 I had originally thought that running a little less since it was empty would be OK.

what I found was not so much a problem with uneven wear but poor handling. Steering was a bit soft and not as responsive.

I went back to running the pressure stated on the door tag. 55 frt 80 rear. Definitely tracks truer and responds to steering input better.

I'm sure I could get away with lowering the rear to 55 as well since I'm not carrying but a couple hundred pounds more than empty but that means added rolling resistance.

And on another note I have read several times from different articles that lower tire pressure is a bad deal in the wet! One of the videos I saw was made by a tire manufacture that videoed the tire through glass as it passed over in the wet. It was a remarkable difference when the pressure was to low as it would not pass the water through the tread as it should have, therefore causing early hydroplaning.

For those thinking they could get by with temp measurement like a race car...I think not as one we don't really have a spec for that temp, along with the outside variable air temp and how hard you really are on the tire. Consider it could be a cooler than normal day versus a hot day versus the speed and road conditions.

An easy drive down a mountain road versus a hard drive down the same road could certainly result in widely varying temp.
And if you are going to try that, you need to get those temps as quickly as possible after stopping the vehicle otherwise your temps are going to equalize and be useless.

Thanks Mike

I appreciate your comment about running with the weight as per the door and the differences in handling. I've always run my tires near max pressure for good tire wear and mileage but wasn't sure if I should with these Michelins.

Measuring tread depth every thousand miles is not a task I'd ever continue doing on a regular basis and I agree with your comments on measuring temp - that's fine on the racetrack, not practical for daily driving. 

I need simple - check the pressure, add more air or let some out...

Just out of curiousity I'll borrow some sidewalk chalk and test the pressure that way, if I ever get dry pavement up here. The thunderstorms and heavy rain are finally melting all the snowbanks, now we'll get flood watches...

 

[SternWake]

I find that tire PSI is something that is quite misunderstood by even those who should know better.


The placard on my door jamb says 32 PSi or something to that effect, and the tire shop, and Smog testing places no matter what, set these pressures.

However I do not have stock size passenger tires, but  slightly oversized light truck tires, so setting these at 32 is way way too low.

My tire max PSi is 50, I found 44 to be how they wear the best.

32 PSI is what I drop them to when offroading or travelling on washboard, and this pressure on Road is Squirmy, loud and unsafe feeling, yet the dang powers that be have these two institutions lower my PSi to unsafe levels.

I'd be really PO'd if i did not carry my own air compressor but had to pull up to a gas station coin operated machine after a Smog test.

I once had Discount Tire rotate my tires and saw them deflating my tires, and the manager shrugged and said they had to set it to what the placard demanded, even though they were different tires from stock, requiring different pressures.  Asinine and contemptuous.

 

[WheelEstate USA]

Stern Wake...I had a battery put in under the hood at Wally's and told them to leave my tires alone. The shop guys jacked the air up to 80 due to the door tag. At that rate it rides like its on rock tires, Flintstone style.
They said its part of the service they must perform...Hogwash...Its my rig and don't screw with my tires or anything else when I only asked for a damn battery.
I hate having anyone lay a hand on our rig anyway. Seems something always happens right after they screw with it.

 

[SternWake]

I once was asked by a friend to change the belts in his Nissan before a X country mission but found one bolt seized, and told my friend I was not going to attempt to complete the job because of it. Had the fastener broke in the block, the vehicle would have to be towed as it could not be left overnight or worked on at leisure.

I had known that the exhaust manifold bolts/studs on the particular engine were known to loosen up and allow the manifold to warp and saw that his was still fine and made a remark about it

He took it to a mechanic for the belt change, and after paying a ridiculous price, I inspected their work, and found the manifold bolts had been deliberately loosened on one side. He got all irate, went back to the mechanic, caused a stink. Cops became involved, things got ugly, lawyers were called, and eventually he just gave up much poorer for the effort.

This type of ' job security' disgusts me and inspired me to learn all I could and do all my own work.

Raising or lowering tire pressure after techs are mandated to screw with it, by Idiots elected into office to envoke nanny state laws, seems harmless in comparison.

Last person besides a smog tech or tire installer to touch my vehicle was a driveline shop who rebuilt my rear axle in 2008. Anyone approaching my van with a tool in hand will find me with a larger heavier tool in hand blocking them.

There are a few local mechanics i would trust, but I don't necessarily trust those they have working for them.

 

[WheelEstate USA]

There's so much I'm physically unable to do now days, but must maintenance I can take care of. I prefer changing my oil, belts, etc. I'm not equipped, nor able to do extensive motor work or R&Rs any more. Oh forbid I should have a tranny problem or anything else serious.
My other issue is being on oxygen I have to be extra cautious around oil/grease or it could be a disaster....as in, how do you spell "explosion" :s 
At 6' tall and 119# I can barely lift half my weight. You might not think so, but it makes for a piss poor mechanic when it comes to leverage and common lifting, like that alternator down in that tight spot.
Margie can lift 5 gal of water easier than I can.

Don't get me wrong...I have a "can do attitude" and will try my best before calling for help, but I'm growing to know and understand my limitations and to live with them as comfortably as possible.

And BTW...I can't lift the spare (full size) tire by myself and the ones on the ground are even heaver :dodgy:

 

[WheelEstate USA]

Sorry I kinda took it off topic. 
I'm just really tired of hearing tire shops, battery installers, etc including messing with things set the way I want them.
Tires are one of the things that I have a constant eyeball on and I can see clearly how they are wearing....as in, not much at all after a year of hard use, much of which was offroad.
I dare say we'll get 5 yrs out of this set that was installed last April 1st.

Short tale....
A friend had 2 tires put on one month and 2 the next. He declined the road hazard that was offered both times to save $10. Two weeks later he got an irreparable hole in a sidewall (from a stick) on one of the newest ones out on BLM land. It cost him the full price for another tire.
My opinion is, we live in these rigs and rely on them to roll. Take the hit on hazard protection. Arrangements can be made between companies to cover replacements, even with Walmart tires...You just have to go thru their BS. But, can you afford a new tire out of pocket or will you spend a little time out of your day to get fixed up on the paper trail?? 

 

[highdesertranger]

here is how I like to run tires. if you are close to the weight rating of the tires, run close to the max psi of the tires. notice I said tires not what that stupid sticker says. likewise the lower you are from max weight rating of your tires, lower the psi accordingly. I use this as a starting point. I really don't have a scientific formula for this. then I adjust according to the profile of the tire and the handling. your tread portion should be the only part of the tire that comes in contact with the road. if you are at max psi and your side wall is close to the pavement your tire is overloaded. with duallies rear the tires must never touch each other, if they do you need more psi. hope this helps. highdesertranger

 

[MK7]

More air pressure gives you a little better gas mileage.

 

[LeeRevell]

I absolutely believe in paying the pittance for hazard protection on new tires! Twice I have had damaged tires replaced with no out-of-pocket cost for me. It is so worth those few extra bucks!