Pressure Gauge - which one works?

Good question. Apart from the National Standards Laboratory, you could get your three pressure gauges tested by an independent instrument calibration company. Won't be cheap though.

You could test several service station gauges (considered notoriously inaccurate) and take a mean figure. Then extrapolate those results against your gauges' results and work out an average figure that you are happy with.
cheers
Gary

Next question is to what accuracy? :o)

Reckon the nearest 1 psi is pretty good, maybe 2 psi would be OK?

If you are getting a difference of about 5 psi, through that one out.

Tyre pressures are all a bit of a dark science anyway.

So it really comes down to what works for you on your vehicle in which situation.

Even if the gauge is out by 10 psi, at least it lets me know the tyre is maybe 15 psi down from the first reading.

The more money you spend, generally the better gauge.

Pick 1 of the 3 that you have , shove the other 2 away somewhere "just in case" and only use no1 all the time , makes no difference if its out by a couple of psi or even 10 psi , the main thing is to have a consistant reading that you know is good for your current situation , IE: gauge tells u that u have 40psi and u want to drop by 20 psi , makes not 1 bit of difference if your no1 gauge is OUT , you are still only dropping your pressure by 20 psi.

Go to somewhere like Bob Jane Tyre mart. Ask them to check a tyre with their guage. Then check the tyre with your three and then use the one that was the closest. If still a bit out, at least you will know how much.

KenD
Bris

The average tyre pressure gauge is not a calibrated device so variability is quite common. We tested 20 over a training weekend and every single one of them read the same tyre differently. Depending on quailty, no gaurantee though, you can also see variability in readings at different pressures as well.

So it really is both common and not really a problem. The trick is to use the same one constantly and you will therefore have a benchmark. After that all you need to do is make the standard pressure adjustments for sand, rocks etc and then if you get stuck use the same gauge to lower a few psi so the next time you know that your guage and those tyres work best at ??? whatever it was in those conditions.

We use three. One for our polyairs which is more accurate at lower pressures, a digital one and an analogue one as well. Variability between all three is between 2-4 psi. I use the analogue all the time for consistency when running sand and rocks.

Regards

RobA

I remember one guy on a training weekend who kept bogging down when everyone else was getting through. I checked his tyre pressures and my gauge said 30psi. He said his gauge said 20psi. Ended up he was reading off the kPa scale instead of the psi scale, and was dropping off the zero.

I have most faith in the digital gauges. I have 2 that read the same and a couple of dial gauges that read a little different.

I noticed last time i was at the ARB store that they have a large face dial especially for low pressures .

Pick the one reading in the middle of the three and put the others away somewhere save and hard to find.

Pooley

I find the comments like "does not matter if it is out by 10 psi" very interesting. That could mean when one the road at say 38psi you could actually be at 28 or 48. in the sand you could be 28 instead of 18. A while back I was out with a mate on some big sand dunes. He a a 60 I had the 80 series. I had my tyres at 20psi he had his at 18. On a big dune I got 3 quarters up and bogged down while he sailed pass to the top. I dropped mine to 18 and from the bogged position drove out and to the top. So does 1 or 2 psi make a difference, sometimes it can. The other thing is testing 20 or so gauges on the same tyre would change as each time you connect /disconnect you loose air. I can garrentee when towing a trailer in soft sand or climbing a monster dune tyre pressure is critical. The better quality gauges are better but a good knock when off road can stuff a gauge quickly. Don't just throw them in the box with all your recovery gear.

Josh

It is possible that all 3 gauges meet manufacturers spec.

Eg they might all be made to be +/- 10% and perhaps they all are.

Even in industrial pressure gauges (I used to be an instrument tech) the accuracy was 1.5% of FSD on most run of the mill pressure gauges.

I bought a tyre adaptor for my compressor, threw away the gauge and fitted a new one that I callibrated on a dead weight tester. The accuracy is now 1%.. but is a pound or 2 either way really a big deal for road use?

I'm not so sure it is.

Cheers

Mark T

Hi Santa!
I have a Michelin tyre gauge(about $40 10 years ago) I used on the Ducati. I found 1 psi made a huge difference to handling. It is very accurate, hence the price but it shows up every other unit I've used.