Pencil Tire Gauges

Years ago Click and Clack complained that pencil tire gauges were junk. I have had $.99 to $10.00 pencil gauges plus ones that were supplied by the car manufacturer (Two bueatifull Rover 2000 guages). They all read accurately and 30 years old. There is virtually nothing to go wrong wear out or break on them. My experience with bourdon tube (standard rotary gauges)is that they have a limited life, variable accuracy and are not shock resistant. I vote for a pencil gauge. Thanks, Bruce

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If you use them regularly and read them carefully, they’re okay. Most of them that I find sitting around in my cars’ gloveboxes get sticky and the little stick gets stuck and doesn’t come out as far as it’s supposed to, giving a low reading. Even new ones will often give you different readings depending on what angle you hold them at too. I bought a bunch of $2 dial-type gauges on sale at a ranch supply store here a while back and I’ve been very happy with them. They’re easy to read, the reading locks in and they’ve so far been very reliable & accurate.

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Pencil gauges can be either accurate or not as can any gauge, bourden tube, electronic or whatever. The only good way that you can know if your gauge is accurate is to have it calibration checked by a scientific instrument calibration service with standards traceable to NIST. People here often pronounce their gauges as being “good” but have not, apparently, had them inspected. They simply paid a few extra dollars and then proceed to believe that they have an accurate gauge. You can pay a lot of money for a gauge and hope for the best but if it has not been calibration checked, then you just don’t know if it is good. Typically gauge mfrs do not specify how they can say why their gauges are accurate and specify no periodic accuracy inspection nor do they specify how the gauge is to be safely stored to preclude damage to its accuracy. An electronic gauge is not magic; can have inaccuracy in it’s pressure transducer.

My “good” pencil gauges that match my $15 dial gauge that has not been calibration checked, work best in cold weather if they have been warmed first in my hand.

An gauge no matter how inexpensive should be carefully stored in a safe place and inside a protective cover such as a plastic bag.

The bottom line if you don’t choose to spend $30 to $50 to have your gauge checked is to spend about $15 for a dial gauge and store and handle it with care. Vehicle tire pressure, fortunately, is not particularly sensitive to inaccurate pressure. Plus or minus 2 psi from perfect is good enough.

I like to say that you need two gauges; one to keep as a reference stored in a safe place and also a “working” gauge that you use, drop, lend to the neighbor, and let the kids use.

You can compare your gauge to whatever collection of gauges that you might have along with comparing to what tire sellers have to arrive at a consensus which is still not guaranteed as good as having it calibration checked at a place with a standard traceable to NIST.

I think it has more to do with the quality of that gauge than the type. I still use a VDO dial type gauge that I bought about 25 years ago (I think I paid about $40 at the time), and it seems to agree with other good gauges. Unless you a playing around with balancing the pressure in racing tires, any decent gauge is probably good enough.

Spray some WD-40 or other similar lubricant, pull out & push in a couple of times & the stick will work fine. Wipe clean after. I did & I still have it (bought years ago).

As with anything, I suspect you get what you pay for. I bought a $2 pencil gauge not long ago at a gas station - I went to use it, and when i pressed it to the valve, the whole cylinder part shot off and over my shoulder! I was like, damn. I pieced it back together and banged it on the ground a bit-- works fine now.

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I have had a pencil type guage for years. It works fine. While at Sears, buying 4 new Michelin tires, I had two mechanics check my tire pressure with their large pencil type guages. One matched mine. The other was off by about 4 lbs. Then we got a third to compare, and it also matched mine. So, you never know. At least I know mine is ok.

I have 3 pencil gauges and 1 dial - no two read the same - though all w/in about 4psi of each other.

I’ve often wondered how to find out about their accuracy - but the NIST approved scientific testing route seems a little extreme. Any suggestions on how to really figure it out w/out the extremes?

Times haven’t changed. WD40 is still goopy and leaves a residue wherever it gets sprayed. $2-10 is still good enough for 2-3 pencil gauges whose readings we can compare with each other - or with our portable tire inflator - or the unstable analog gauge that we have checked annually by our friend at NIST (unless we just go and get a job there for lab access).

Clean that gauge every decade or so. Take it apart, soak everything (except the rubber, which should just get water-washed) in alcohol - not spirits, which have sugar (but can be refreshing with ice if beer is depleted), air-dry and reassemble. Easy-peasy.