Topic: How do you know when your tire gauge is no longer accurate?

[Bulkley]

Some years ago I found the sweet spot tire pressure for the car and tires I had at the time was 39 psi.  I used that for months.  For some reason I acquired another gauge and found that my old trusty gauge was reading 4 or 5 psi  higher than the new one.  Recently, another one failed high.  Do they always fail high?  Does the spring get weak? 

Cruising the gauges at Canadian Tire and Lordco I noticed that most gauges have a +/- accuracy of 2 psi which is not accurate at all as far as I'm concerned.  I did find one with +/- 1 1/2 psi; marginally better.  My present most trusted gauge is a digital one handed out to customers at our local Mazda dealer.  Is it any better?  I don't know who made the gauge or what its accuracy is. 

The only way I have found to test gauges is to test several at the same time.  If 5 gauges read the same and one is wildly different, throw it away. 

Thoughts?

[HeliDriver]

I haven't owned a pencil-type gauge for probably 25 years. I currently have a few different brands of digital ones, and they all seem to read about the same and work fine.

I've been tempted a few times to buy an expensive ($80 or so, IIRC) hose-type gauge with a pressure release, but have never pulled the trigger. Would have been handy for adjusting pressures during track days, but I don't do that anymore. Would be overkill for day-to-day use, IMO, when the cheap digital ones do the job just fine.

[safristi]

A:  when you have a tire gauge................... ...buy a decent tire pump and check yer tires and the blow up dolly frequently..................    she will squeak when LOW

[ktm525]

When you no longer are able to achieve that smooth no-bump ride. 

[tpl]

I don't really care if my gauge is +/- 2 psi...and neither do my tires.  The specified pressures are 29 psi to 32 psi if people are in the back seats.  I set them to 34 on my gauge   AND I ALWAYS use the same gauge.     The tire place I use has a fancy gauge and they set the tires to 32 which, within the width of the needle agrees with my gauge

[84im]

I have two expensive tire gauges, both with a rubber hose and pressure release button.  I bought the first one for my track days and the second so I could set the correct pressure on my F250.  I couldn't use my first gauge when checking the tire pressure on my truck because the gauge only went up to 60 psi and the truck tires needed to be set at 65 psi.
To me it's worth the money and the gauges should last a long time.....unless I drop one of them.  They really don't like being dropped. 

[EV Dan]

It's not like the gauge will be off +2 psi on one tire measurement and -2psi on another. I imagine it should be off by the same number for all the tires measured. I bought a fancy gauge at CT that came with a padded storage case. It always works an is accurate. I keep my tires at 35psi.

[wing]

I think the plus minus 2psi is more of a warning.

I bought a few cheap ones.   They both read the exact same number when I test.   And the Tpms sensor on my truck also matches that number.

I consider these $15 gauges accurate enough now and don't question them.

Princess auto one was cheap.   It's a Chuck type for filling as well and allows release,  so convenient.

[Ex-airbalancer]

It only cost me $135 to get a  instrument  certified for calibration that reads PSI , I could give you the number and you could ask them to calibrate your pressure gauge