I have two gauges that differ significantly, which raises a question. If I only had one gauge and it was off, how would I know? Is there some way to verify the accuracy of a pressure gauge? Another variation of the question: Can anyone recommend a very accurate tire guage manufacturer? The liquid filled gages typically have a bleeder screw. Sometimes it's under the rubber or plastic that surrounds the gage. If it has this, open it up remove it then close it again. I think some air is in the gage. I was told by Archer Brothers Racing that sometimes when transporting these gages over the mountains the gages will not read correctly. In my case my gage was reading about 4 pounds high and I was starting several races in my Spec Racer Ford with only about 19 pounds of pressure in my 048's when the gage had said I had 23 pounds. Typically I would try to set so the 048's would be at 28 to 29 pounds hot. When cornering at speed the car was rolling over on the tire. I'm lucky it did not come off the rim. I would definately recommend a liquid filled gage. All Race shops will have them. The quality tire gauges have specifications for that sort of thing.

Mine (from Racerpartswholesale.com) is guaranteed to be within 1 1/2 percent over the entire range. They're not very expensive either ($30-40). I found a link:

http://www.racerpartswholesale.com/tirega.htm

Mine is the 'ultimate' and I've been quite happy with it. The hold valve in the 'even better' would probably come in handy, but they didn't have it when I bought mine (and paid more...). I've been using a digital gauge... can it be trusted?

Orrie I had a budy of mine trying to improve his motorcycle riding skills for about a year. I was giving him instruction to do so. When we would leave my place he would always do well. When he practiced on his own he wouldn't do as well. The difference? When leaving my house I would inflate his tires to my prefered settings. When he would do it himself he was riding with too low of a presure. The reason? His gauge was off by more than 10lbs.

Buy a couple of gauges. Always check them against each other. If both go sour then your luck is worse than you know.

I have five or six tire gauges, and none of them agree.
The Racerwarehouse 30lb one seems to be the most... disagreeable.

The digital ones (showing only 0.5 psi) seem to be the most consistent, but none of mine are what you would call "professional" and none are fluid-filled.

I do have an Omron labratory pressure gauge somewhere I should try calibrating against, if I can wrap my head around the whole Pascal thing.. 10,000 Pascals = 1.4503774 PSI I wondered the same thing, its a good thing i've got access to a tire/wheel lab and can compare my gauges againsts a calibrated gauge :-)

I recently dropped my cheapo dial gauge i bought at Murray's Discount Auto and now it is over 7lbs off. I was looking for a digital guage to replace it (hoping they are more drop proof) and I found a series of digital gauges at Sears from a brand called AccuTire. They have 3 models $10-$24. They all have the same stated accuracy so i went with the cheapest one (smallest, fits in the car better)

http://www.sears.com/sr/javasr/produ...id=02823010000

Range: 5-99 psi
Accuracy: +/- 1% + 0.5 psi
Oper. Temp: 0-100F

for a 30psi tire, you're talking +/- 0.8 psi which ain't bad. I bought two and they both measure almost always the same, occasionally 0.5psi off. I will take both of them to the lab when I get back to work and let you know how close they are two the "true" pressure. Note, the battery is unchangeable, but the warrenty is 5 years, so I'd imagine it has to last at least that long.

There is no AccuTire website, but this was on the packaging: www.msiusa.com, I'm assuming that's the manufacturer of the actual sensor.

And the one I bought is extremely lightweight, so that should be pretty orgasmic for a lot of you. (fyi, its so light it feels cheap, but i'm guessing the guts are the same as the more expensive models) http://www.canadiandriver.com/articles/pw/michelin.htm

that is my gauge, bought it at sam's club for $20 Mostly you need consistency and repeatability. I generally use a cheap, tiny gauge that I first compare to a known good one in the pressure range of interest. Then I just add or subtract the amount needed when I actually use the gauge. If you keep the thing safe, it will tend to read consistently. Here's one I painted Saffron Yellow (not yet cleaned up) for kicks.

i just ordered from sharper image this compressor.


http://www.sharperimage.com/us/en/ca.../sku__SI262BLK

i havent received it in the mail yet but it says its accurate to 100 psi...but whatelse would they say.


how much psi should the lotus elise non sport tires be inflated to without warming them up first? i guess its the cold-pressure i am looking for. The built-in pressure measurements in the compressors I have seen are way off. I'm not even looking at mine. Then again, I use the cheapo compressors from Walmart, just got myself a new one for $10 (after damaging the old one by driving over it ). But I wouldn't trust the Sharper Image one either.

I use a QuickCar pressure guage. They're very nice. I haven't systematically compared the values to other guages. One time I borrowed somebody elses (digital) guage, and it read a few psi different. The QuickCar costs around $30, available at http://www.soloperformance.com. Mostly you need consistency . . . known good one . . . ]
Yes, and therein lies the question. How do you know you have a known good one. I've been searching the net for info on this and one site suggested comparing it to the gauge at an airport which is required to be calibrated to a standard.

Without an easy way to periodically check at least a couple gauges, I'm not sure how you could really know what you're tire pressure is. Buy a good quality gauge $15-30 and use it and only it on the car.
The cheopo gauge that Stan has pictured is really close to the expensive ones, but the key is one specific gauge for the car.
I have four different gauges for four cars and then a dedicated gauge for my R-compound tires.
m I use a QuickCar pressure guage. They're very nice. I haven't systematically compared the values to other guages. One time I borrowed somebody elses (digital) guage, and it read a few psi different. The QuickCar costs around $30, available at http://www.soloperformance.com.
Wouldn't you know it, I use the same gauge and got from the same people. Yes, and therein lies the question. How do you know you have a known good one. I've been searching the net for info on this and one site suggested comparing it to the gauge at an airport which is required to be calibrated to a standard. Without an easy way to periodically check at least a couple gauges, I'm not sure how you could really know what you're tire pressure is.
You only need to do this once. If you have several gauges and they all read 27-28 on a tire and the cheapo reads 24 then it's 3-4 pounds off. If you add air to the tire and the other gauges read 29-30 and the cheapo reads 26 then you have the relative change you require....everything moved up by 2 psi. You can also borrow a gauge, stop in any decent shop and check theirs, etc, etc. After that, you use the gauge you have and then say at a track or autocross event you add some more air, and adust the handling a bit by, say, dropping one relative psi at one end of the car. The little gauge I showed above costs like 5 bux and samples are never right on, closest I've seen is 1-2 PSI off. The main thing is that it always reads the same number for a given pressure, and that it is reliable for relative changes (which is easier to achieve than absolute accuracy). You could relabel the dial or reposition it on a gauge if you wanted. I just magic marker the calibration number on the back or just remember it. Works fine. The thing I love about that tiny gauge is that it's easy to keep in your pocket at all times. And it's so small that when you check the pressure, if it is too high, you can just tilt it to let air out so that you can drop some pressure. Very simple.

Whatever you do, you need a gauge which you trust and have confidence using. Nothing like peace of mind! I wondered the same thing, its a good thing i've got access to a tire/wheel lab and can compare my gauges againsts a calibrated gauge :-)

I recently dropped my cheapo dial gauge i bought at Murray's Discount Auto and now it is over 7lbs off. I was looking for a digital guage to replace it (hoping they are more drop proof) and I found a series of digital gauges at Sears from a brand called AccuTire. They have 3 models $10-$24. They all have the same stated accuracy so i went with the cheapest one (smallest, fits in the car better)

http://www.sears.com/sr/javasr/produ...id=02823010000

Range: 5-99 psi
Accuracy: +/- 1% + 0.5 psi
Oper. Temp: 0-100F

for a 30psi tire, you're talking +/- 0.8 psi which ain't bad. I bought two and they both measure almost always the same, occasionally 0.5psi off. I will take both of them to the lab when I get back to work and let you know how close they are two the "true" pressure. Note, the battery is unchangeable, but the warrenty is 5 years, so I'd imagine it has to last at least that long.

There is no AccuTire website, but this was on the packaging: www.msiusa.com, I'm assuming that's the manufacturer of the actual sensor.

And the one I bought is extremely lightweight, so that should be pretty orgasmic for a lot of you. (fyi, its so light it feels cheap, but i'm guessing the guts are the same as the more expensive models)
Just an update folks. i tested both gauges multiple times against our calibrated gauge. At 30psi, one gauge read consistantly 30.0, the other 29.5 (0.5 psi resolution) Now that I'm curious, I'll have to check them again in 6 months or so to see if they have drifted. and no, I won't test them after dropping them...unless of course i actually accidently drop them Just an update folks. i tested both gauges multiple times against our calibrated gauge. At 30psi, one gauge read consistantly 30.0, the other 29.5 (0.5 psi resolution) Now that I'm curious, I'll have to check them again in 6 months or so to see if they have drifted. and no, I won't test them after dropping them...unless of course i actually accidently drop them
So...as mentioned above about consistency, you are all set with either of those gauges. Pick one and stick with it.