Accuracy of tire pressure gauges?

[TGinAZ]

Like many, I too have wondered about the bounciness versus pressure in the tires. I read about the chalk test and tried that. What about tire brand and size? How about two-wheel versus four-wheel drive? And don't forget about options like the FX4.

I have a SuperCrew FX4 XLT. The door pillar sticker says my tires should be inflated to 30 psi.

My observation is that at 30 psi my truck is bouncy... much more than my wife's RAV4. At 38 psi it's still bouncy, but subjectively I couldn't see a difference. At that higher pressure, however, I seemed to notice road imperfections more... every little stone and crack in the road was transmitted to me and I felt it more.

But that's not the reason for this thread! It's a question I've asked elsewhere and many years ago...

How does one determine the accuracy of their tire pressure gauge?

Years ago I had a collection (8-10) of all sorts of of gauges. One day I gathered them all and compared their measurements. I saw as much as a 12 psi variation. There seemed to be no correlation between the style or cost of the gauge. Pencil, dial, digital... fine versus coarse graduations... it didn't seem to make a difference, there was just a lot of disparity.

More recently: my Ranger console display indicated 30 psi, and then 38 psi (when experimenting with pressure). My digital hand-held gauge said 32 psi and 36 psi respectively. That's just weird!

So my question still stands.... how does one determine accuracy???

Sponsored

 

[HenryMac]

So my question still stands.... how does one determine accuracy???

Really want accuracy?

My gig before I retired was engineering, designing, and building ASME Code Pressure Vessels. As you can imagine after they are built, they are tested using calibrated pressure gauges.

We had "Master Gauges" that were sent out for calibration on an annual basis at a shop certified to do calibration. https://www.trescal.us/customer-service-bulletin/pressure-gauge-calibration These were not the gauges we used on a daily basis. The Master Gauges resided in the tool bin. When a working gauge was needed for testing a pressure vessel it was hooked to the manifold the master gauge was attached to, the manifold pressurized and thus the working gauge was compared to the master gauge.

We had dozens of master gauges. Why? You selected a gauge where the pressure you needed was in the middle 3rd of the range of the gauge.

So for a 100 psi vessel test you couldn't use a 600 psi gauge.

All this ensured accuracy.​

What I do as a retired guy

I've got about 5 of the pencil type tire gauges, the ones they give you at the local "Tire Discounters" place. When I check tire pressure I always grab (2) and verify they read the same pressure. If they don't, I grab a 3rd and find 2 that match, and throw away the odd ball.

I compare that to what the vehicles on-board computer says. It's always within 2 psi.

Good enough.​

 

[weasel1]

I happen to have a handheld digital and it's spot on with with the Ranger and my Colorado. I had a really nice dual gauge that I'm having a hard time finding a replacement for. If you have a couple and they read the same, then they are probably right. Close enough is good enough, just like John said.

 

[FULLSCALE]

I’ve always used a good Milton gauge, the kind with a large 2” or so face. Not sure how long I have had it but it’s very accurate to what the truck says is in the tire.

 

[HowIconic!]

I use a Steelman Digital Inflator. It is very accurate. Bought from www.toolto
ia.com.

Sponsored