Almost blew my tires today.
 

I was checking my air pressure today at a gas station and was shocked to see my PSI drop to 26psi from the 46 that I had inflated them to a few weeks ago, so decided to do something about it. I start adding air, and was surprised that it was taking a while. It wasn't until I got to the last tire that I realized that somethind was rotten in the state of Denmark, so I got my own pressure guage out and did a comparison. According to the guage on the air machine, I was at about 45 psi, but my own guage read over 80! My tires are old, and it's time for new ones, but that impressed me. I was thinking for a moment of driving with the tires like that before decideing that it was a really stupid idea, and deflated them back to 46. Scary **** though that an air pressure guage could be so far off when so many people use them. Do the gas companies install bad equipment, or was this just some freak wrong reading?

Occam's Razor postulates that the more likely explanation is that it was some freak wrong reading. This freak wrong reading is possibly a consequence of damaged or poorly maintained equipment.

Do you use a digital tire pressure gauge? in my opinion, i'ts the only way to go.

On an unrelated note, my car's ride was becoming more and more bouncy as time went on and I could not figure it out what it was from.

Then one day I noticed a large bulge sticking out of the tire. On the way home I discovered the ride got smoother the faster I went, haha. Not being a rocket scientist in the common sense department, I decided the best way to save the suspension from damage, I would cruise along at 85 mph. All was fine for a while when BLAMO!! my tire blew out. I quickly pulled over on the side of the road to inspect the damage. I notice the tire has a hole in it about a foot in diameter! That's when a trooper pulls up behind me; I was sure I was getting a ticket. Luckily the trooper had even less common sense than me! he saw me with the jack on the side of the car, and told me I should stay on the other side of the car for safety.

Nope, no digital one, but the one that I keep in my glove box is clsoe enough for me.

The Battle of the Bulge
 

Despite the pressure, the bulge is simply a broken steel belt which can wreak havoc as you experienced.

Now with the cheap-*** gas-station pumps, is it even possible to inflate a tire to a dangerous level...

...and besides that, I've heard of tires blowing out due to under-inflation, but almost never for over.

So what exactly would happen if we ran 80 psi in our tires? (I know it's a dumb question, but I need a mental picture).

RH77

...not particularly eager to find out the hard way. I assume that over 80 PSI on a car in bad need of new tires is dangerous overinflation. I was surprised that the tires could handle it as it was. That was the point where it stopped going in though. That was what made me realize that something was wrong.

I am more concerned with how easily the steering it moving at 10,000 miles now - hope the higher pressure isn't jolting the suspension too much.

I have a couple of gauges - one digital good for up to 50psi in 0.1psi resolution and just a pistttts of air while checking the tire can drop the pressure 0.1psi. I have another one the I bought when I got my first car back in 1972 that is still within 1psi when checked with the digital gauge. The third gauge goes up to 100psi for checking the spare (60psi) and other higher pressure tires like my scooter and bikes. Then the gauges on my two air tanks and the one on my pressure regulator.

Steel belts are in the tread area only - polymer belts are in the side walls and tread areas.

I don't trust the gas station air compressors. My craftsman air compressor does a better job and it will work off my cigarrete lighter. I keep it at home and pump my tires every 2 weeks. I use a digital tire gauge instrument and it never let me down, except when the batteries died.

I should look into one of those compressors. How high is it good for PSI wise?

I have my tires at 55psi. The compressor only costs $30.

And thats why I live in Finland - not stinky poo at all here. (unless the wind is blowing in from Russia)
https://www.emmyvideos.com/conanFinland2.jpg

Digital vs. Analog
 

Back when this became an important realization at GasSavers, I sprung for a decent, racing-grade guage.

The gauge housing has a rubber surround to protect it from getting battered, and it holds the pressure until you press a button to release the air it's stored. I once had a digital keychain guage, but it was fairly unreliable and gives the "digital effect" -- e.g. digital speedometers. Sometimes a number needs a visual reference around it (analog).

It's spot-on -- and if you're fiddling with lining-up the guage inlet in cold weather, the design lets you get the maximum value stored to compare with the next tire once you get it on there properly.

I found it at the Auto-Parts store for about $25. Now all I need is that "laser" (Dr. Evil reference) that gives you temperatures of it's target. :)

Rh77

Brian O'Conan
 

I still can't believe that Conan O'Brien probably helped your PM, Tarja Halonen, win the election. Now that's funny.

Be Cool my Babies.

RH77

You paid too much - JobLot or Harbor Freight for about $12 and they get up to about 100psi but if you run them too long they over heat and can blow the hoses or pop the one way inlet valve. Ask me how I know . . . but they are simple to fix most of the time. I use them to precharge an air tank because when it is cold outside I don't like to wait for the air to get in the tire plus it gives the moisture to seperate in the tank so it doesn't get into the tire.

Yea I bought one of those and the you're right on about the hoses. The gauge is extremely inacurrate above 40 PSI. Spend the money for an accurate gauge if you're planning on running max sidewall pressure or greater.

RH77 "So what exactly would happen if we ran 80 psi in our tires? (I know it's a dumb question, but I need a mental picture). Nothing when running Dunlop 185/70/R14. The ride is harsh.

Well . the other guy that was campaigning against her is a bit of a no personaitly , personality.
I dont think anyone even knew his name.,,,, and to win , i think thats important. :D

Around here we have Sheetz gas stations that have of all things free air machines. They are the kind that you dial the PSI that you want and it rings as it pumps and when it stops ringing you are at the set PSI. Of the 4 Sheetz that I have stopped at and filled air (I always check my air when I am there) the closest to real PSI was 10 off. One I had to set the dial at 80 PSI to get to 50. So I always only trust my gage.

Seeing that I can see how many people are driving around with 1/2 flat tires if they trust those things.

80 PSI - well at some point the bond between the rubber and the cords starts to bread down and let go then a bubble appears and the tire blows. When I had my brother do the inside patch to my left rear tire I was amazed at how thin the tread area was and the side wall was pretty thin also. Considering a steel air tank max pressure is 125psi putting 80 in a rubber tire and then bouncing it down the road . . . hummmmmmm.

I havne't been in the back room of too many gas stations, but the ones i have been in all have big standard duty air compressors. The one at the station I work at is a big heavy duty Craftsman one. Plenty large enough in my opinion. BTW I think most stations keep thier air tanks at extra high pressure to keep filling times down. If they only had 45 psi in them, it would take a lot longer to fill than if they kept it at 100 psi.

are there any key chain gauges that are garentied to be acurite? we have a drawer full of the pen style gauges, and I think we finely tossed the ones that didn't agree with each other.
I tend to top off my tires with a hand pump with a gauge on it, it's a little slow, but extreamly portable, and it's rather acurite up to something like 150psi.

Of all the people...
 

Of all the people who promotes a simple way of living, I'm surprised you have a fancy digital tire gauge. You're like an Amishman with a Tempo ;) Calm down, I'm just bustin' your chops Pops.

The reason for the analogue perspective is this: e.g. you have a tire that's severely underinflated. With the analog gauge, you can see via hash marks that "I need 20 more lbs." With a digital, you have a number and have to do some Math. I dunno -- maybe it's just me -- I tend to be a visual processor of information, and it's easier to calculate how much time that pump needs to be attached to the valve stem.

Ryland - those old pen-style testers were good back in the day, but became "cheap" over the years. If you can find one from the 50's and 60's, then you actually have an instrument. The Digital guages are, for the most, accurate. I got my old one free from the TireRack when I ordered a set of tires. I used it during Autocrossing and it seemed to be right on the mark to show the increase in tire pressure as the heat of tire rose.

RH77

I knew Dracula before he could count !
1 pound per second...for how big a tire? Large volume tires fill slower (from the same source), tiny tires fill NOW!
Ah! The gauge knows! It's easier to "bleed down" than to refill & refill! I'm just pulling your chain....
:D

Public air hoses suck! As does anything else the public (ab)uses! Your own pressure gauge is essential! Digital? Who need the tenth pound read-out? Did you ever try to read this half pound difference in low-light conditions? ARGH! 21st century clutter! NASCAR is partially responsible for this hair-splitting ( at least the commentators [common 'taters?] are...)"...adding a half pound to the right front!" ...while the car's in the pits. BS!
People drive around on low tires because they don't check 'em! Ever! Ask anyone you know "When was the last time you checked your tire pressure?" You'll get a blank look! "Me"? I rest my case...

They will blow, trust me, done it, seen it. Kind of a strange question for someone titled as a Senior Vehicle Analyst?

It is risky enough to excede the car mfgr's suggested pressure (especially in rear motored cars, not much of a problem today) due to ill handling, but don't bump much above the tire maker's for sure. Anyhow, the max tire pressure is for max load rating too, a lot of older cars, especially European wagons, would have empty and loaded ratings posted for inflation.

And for blowing out for underinflation, I have seen and done it....front right Vredestein on a Toyota at speed....the tire picked up a nail and developed a slow leak that I did not notice, I could see indications of the tire riding on the sidewall for a period of time, it happened on a long trip.

I just rememberd a nifty gauge that a friend picked up from the bicycle shop, you screwed it on to your valve stem, then filled it thru a valve on the gauge body, so you could watch the presure rise, without having another object in your hand.

How long will a digital presure gauge stay acurite? I meen, what do they have in them that reads the presure, and how long will it last?

They have a pressure transducer and should stay accurate forever - they also recalibrate when you turn them on so the 0 reading is nice. They are great for detecting a slow leak because of their resolution - one tire down 0.2psi in a day means maybe 1 psi in 5 days! I even detected a difference in pressure in the right rear because of tire heating by the muffler. They are also good for low pressure tires on ATVs and for that low car tire to see that it had 10.2psi in it. Finally they are great to calibrate your other analog gauges.

What you don't see are the many, many people who never check tire pressure! Never! they are legion! Then, these same "experts" complain about their tire life.... :confused:

not to mention imporperly inflated tires ruin handling and braking as well. I once drove a car that would loose about 2psi/day and I could feel the differnce on corners.