Accuracy if tire Pressure gauges rant
 

Who Knew?
Accuracy of tire Pressure gauges.
I had a full-blown, fully bonafide, lettered engineer tell me one time that pneumatic pressure gauges were inherently accurate.
Many, many years ago.
I took his word for it.

I was just out measuring tire P on a vehicle that demands within a pound or so.
Guess what?
I was looking for 50 spot on
Out of six gauges, three read around 50
The other read 60 to to 64 .
Three read 10 to 14 lbs high, OR, the other three 10 to 14 low, and I don't know which is correct.
Three are regular dial gauge style, the other three are just the retracting stick style .
One is a 30 dollar gauge I bought years ago.
None read exactly the same.
NONE.
Needless to say, this is sort of an eye-opener!
A BFD !

Yes tires dead cold.

Gauge recommendations?
Edit-doing some research here--Most universal gauges are junk !
Like I said, I had no idea......presumption....
it looks like 70 bucks are required to get a "gooder" one?

Longacre .

Forget how it's spelled..but "bourdon tube" is the key. Yes, the more expensive dial gauges have them. I'm still using the one bought off a snap-on truck decades ago...was made in USA then. Today I notice not. Motometer makes a gauge popular among the drag race set.

What vehicle requires 50 PSI ? just curious

Same experience overall. Settled on a pricier one ($100 or so) that matches what my car's TPMS thinks it is, give or take 1 PSI so we're good. In my experience the cheapo digital ones are totally inaccurate.

Interesting video here...

https://www.youtube.com/watch?v=Uzo_2g8oCzU

We rented a car for a mad dash to Dallas and back in rush hour traffic. On the way to my house I noticed the ride was awful. The tire pressure system indicated all normal. It was a Fiat as I remember. It was just a cheap rental.

I whipped out my gauge and it just pegged the gauge. I let a lot of air out, and still bang, pegged out. It took forever to get to the proper pressure. Evidently the car rental place uses that pressure monitoring system to check tire pressure. I bet that tire had triple the max inflation. I was happy to turn it back in.

You can pick up a inflation air fitting and join it to a proper air gauge and make your own, depending what you want to spend on the gauge more accurate then most preassembled.

Deschodt, most HD pick up trucks take up to about 80psi.

It is very unlikely that any measuring device you own is calibrated properly.

A cheap tire gauge? Nope.
An expensive tire gauge? Maybe. But not if it's old.
A sweep style meter? No.
Torque wrench? No.
Vernier? Probably okay.
Micrometer? Likely okay.
Ohmmeter? Likely no.

You should not be surprised.

Back when I raced karts and we were running around 7 psi where a 1/4 psi made a difference, I didn't trust my 0-15 psi dial gauge so I gathered up about half a dozen gauges from fellow racers. About half of them read the same so I calibrated off that but it was still surprising how far off many of these expensive low pressure racing gauges were.

Here's what I would buy. Big armored dial with a bleed valve. The idea is to measure using only 1/2 the scale for best accuracy.

http://www.amazon.com/Moroso-89595-Gauge-Garage-0-100/dp/B01LZOWB10/ref=sr_1_29?crid=34ORL8E0OUTBK&keywords=moroso+tir e+pressure+gauge&qid=1561056921&s=automotive&spref ix=moroso+tire+%2Cautomotive%2C184&sr=1-29

http://forums.pelicanparts.com/uploa...1561057168.jpg

No one (uncalibrated) device should be considered good. Period.

More likely the Yahoo at the rental car place just put as much air in the tires as the compressor would produce...in an effort to not have to mess with the TPM light and he wanted it to last 6 months or more before he'd have to look at it again.

I read those pencil type that you get free from discount tire were on average the most accurate. Ok this was an Honda ody club forum so not sure where they got it from

I'll second longacre.

Yup.

Their pro analog ones are probably best, but I've had this one (pro digi 0-60psi) for 20+ years and it is still pretty darn accurate (as compared to a few different higher-end gauges and multiple Discount Tire $$$ air stations):

http://forums.pelicanparts.com/uploa...1561062262.jpg


YMMV...

I sold pressure gages for years, Wika, Marsh, Hennie and others. If you want a gage to read in the 50 # range get a gage that measures up to 100#. Mid range is the best accuracy reading. We always said that if you have only one gage in line you have your doubt, two gages in line you have an argument and three gages you have a law suit.

The man with one watch knows what time it is. With 2 watches he's not sure.

For what it's worth, I just visited the snap on website. They no longer offer a gauge like mine.

At a hardware store a while ago, I noticed a bunch of thermometers on display.
Pretty wide range of temps indicated, all sitting there side-by-side.
If I needed one, I'd find the average and buy the thermometer with that reading.

I destroyed a rear tire at recently repaved track. My nice longacre digital was reading about 3lbs high. Went with a motion pro dial that checked right on with the tire vendors calibration rig. Also, recalibrate often. Bouncing the gage down the highway in your trailer to the next track, things can change.