Wednesday, February 8, 2023


Tire pressure gauges lose accuracy over time. Here’s how to check them

By Mark Polk, RV Education 101
I talk about the importance of checking inflation pressure in tow vehicle and RV tires all the time, but is your tire pressure gauge giving you accurate information?

When I was in charge of some large fleet maintenance operations, one of my responsibilities was the tool calibration program. Certain tools required regular calibration to ensure accuracy. A tool every RV owner uses is a tire pressure gauge. But did you know a tire gauge can lose accuracy if it gets banged around in your tool box?

I’m getting ahead of myself. Let’s start at the beginning…

I always say you get what you pay for. Lots of inexpensive tire gauges at the auto parts store cannot be calibrated, and if the reading is inaccurate the gauge is worthless. This gauge is the tool you use to check tire inflation before leaving on a cross-country RV trip. This is why you should spend a little more money and get a quality inflation pressure gauge.

Now the question is, can you calibrate your tire pressure gauge? To do it professionally you need some type of standard air pressure reference to measure it against. We all know that is not going to happen, so there are a couple of things you can do to check the tire pressure gauge for accuracy.

How to check the tire pressure gauge for accuracy

  • You can check the air pressure in a tire with the gauge in question and then check the same tire with another quality tire pressure gauge. When there is a significant difference in the readings (3 or more psi) between the two gauges, one or both gauges might be inaccurate. If both gauges read within 1 to 2 psi of each other, they are fairly accurate.
  • If you want a more precise method for checking the accuracy you can purchase a master test gauge or take your gauge to a local tire dealer or fleet truck maintenance facility and ask them to check it using a master test gauge. A master gauge is certified as calibrated and accurate. But I caution you, there are lots of tire dealers who don’t have their own master test gauges checked or calibrated on a regular basis.

Tip: Don’t depend on gas station pressure gauges to be accurate. Gas station gauges are abused and neglected, raising concern over accuracy.

Types of tire pressure gauges

There are several different types of pressure gauges available on the market. When you buy a gauge, always look at how much pressure it is rated for. Most automobile tires are inflated from 32 to 35 psi, so a 0 to 60 psi gauge is sufficient, but motorhome tires can be 100 psi or more. It is important for accuracy and to prevent damage to the gauge that you get the right gauge for the job. A general rule is, find a gauge that reads double the inflation pressure. If this is not possible, try to find a gauge rated for higher pressure, like 160 psi.

The most common type of pressure gauge is the plunge or pencil type gauge. As a general rule, a common plunge-type gauge you purchase will be accurate to + or – 3 percent when it is new.

Like everything else these days, tire pressure gauges are going from analog to digital. Analog tire pressure gauges were the standard for many years, and some people you talk to swear by analog gauges. But advancements in digital technology have improved on that standard. Analog dial gauges are about as accurate as quality pencil type gauges. In numerous tests comparing analog to digital, the digital gauges were more accurate.

Regardless of the type of gauge you choose, there are high-quality and low-quality gauges available. Buying a cheap digital gauge would be the same as buying a cheap pencil-type gauge.

Here are a few things to keep in mind when it comes to tire pressure gauges

1) Spend a few more dollars and get a quality tire pressure gauge.

2) If a gauge is used to check dual tires on a motorhome, the chuck end of the gauge should have a dual foot design to make the job easier.

3) Always select a gauge rated higher than the inflation pressure of the tires you are checking. Caution: Do not apply more pressure than the gauge is rated for – it can damage the gauge and affect accuracy. If you over-pressure a gauge, have it tested for accuracy.

4) Try not to drop or jar the gauge. Store the gauge in some type of protective covering or case in an area where it won’t get hit or damaged.

5) Periodically test the gauge for accuracy. At a minimum, compare it to another quality gauge to see if both read the same or close to the same pressure.

6) After you purchase a quality pressure gauge, use it on a regular basis to check your tires.

Properly inflated tires are safer, extend the life of the tires, improve fuel efficiency and lessen the chance of unexpected and premature tire failure.

To learn more about using and maintaining your RV, visit RV Online Training.

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Digital tire pressure gauge at Amazon



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7 months ago

We just returned from our first trip of the year. We added a TPMS for the TT and I was concerned about the pressure and temp differentials from side to side. Before we left the pressures were equal. When I got home I checked pressures with two of my pencil gauges, both sides were equal and they varied by almost 10 PSI based on which pencil gauge I used. I went and bought a good dial gauge and found that one side was 8 PSI low which would explain the pressure and temp differentials. Yes, a good, accurate gauge is an essential tool to have and they need to be treated with respect.

7 months ago

I agree. Article is a waste of space. This could have been a 2 line quick tip!

Also I have never seen a tp guage that can be calibrated.

The writer mentions it but then discards it because it is superfluous! I would like to know how they are adjusted (not just checked) and model numbers & photographs.

Perhaps this article was written by Johnny?

John Peters
8 months ago

Having a tire gauge will allow you to monitor the air pressure of your RV’s tires. This small device is far more significant than you may realize, therefore you should attempt to get the greatest one you can afford.

8 months ago

I use a long truck type gauge, mounted to the floor by the entry door, an electronic digital gauge, hung on the wall by the entry door and a TPMS system. My home based compressor has an analogue dial gauge. All four are within + – 2 lbs. So, I trust them individually as the situation to use warrants. I checked them collectively against each other, twice a year .

Tommy Molnar
8 months ago

After purchasing my 2016 F-350 (pre-loved), and installing a Banks iDash gauge, I found I could monitor my tire’s air pressure through it. This is how I keep tabs on the pressure in my truck tires. Now I wonder just how accurate THIS method is. I’ve compared this pressure to the pressure shown on my ‘long’ trucker tire pressure gauge and they seem to match.

1 year ago

If you attend an Escapee’s “Escapade” they will check your gauge free of charge.

Jeff Arthur
1 year ago

always find this section amusing. I’m using 3 Milton gauges . All are + – 2 at ranges from 20 psi to 135 psi . Milton are U.S. made ( or were) and yet you recommend “ others “ ( in the past )
Most times I think you tend to over analyze something’s yet trust electronics to do your job for you .
* disclaimer don’t trust anything anybody’s sez as it 100% of the time linked to money

Hook N' Haul 789
1 year ago

Great artcle on tire pressure gauges. Now I am interested in the accuracy of TPMS system pressure sensors on the valve stem. Afer inflating all my tires by gauge pressure, the TPMS system displays pressures differing by as much as 3 psi. Short of rotating the sensors around from wheel-to-wheel for comparisons, how can the accuracy of the sensors be evaluated? Does anyone know if any TPMS manufacturer offers a matched set of 12 calibrated sensors? (Six on the fiver and 6 on the hauler.)

7 months ago

I have the tireminder i10 and use 2 top of the line pressure gauges.Usually my TPMs is about 2 lbs to perfect.What I really like about the monitor system I have is I can reset it daily when traveling as it stores the days pressure and temps.

Roger Marble
7 months ago

Having conducted the only direct comparison of two different TPM systems for both pressure and temperature I am aware of, I find that the claim of +/- 2% accuracy for TPMS to be a reasonable representation. HERE is my blog post with the numbers from my test. That post has links to other parts of my direct comparison for both Temperature and Pressure. To answer what I do for a hand gauge is I have 3 identical digital gauges. I keep 2 packed away as personal masters. I check my regular use gauge against the masters whenever I get a significantly different reading between my TPMS and the hand gauge when setting pressure before a big trip. I figure the chance of my TPMS and hand gauge both going wrong at the same time is very unlikely. Also the chance of all 3 digital gauges going off the same amount and in the same direction is essentially impossible. Yes this is overkill but since i offer gauge checks at RV conventions where I give seminars I feel it is important I have reliable gauges.

Bob M
1 year ago

It would have been nice if you recommended a good quality tire gauge. The article does nothing for me, especially since I’m a retired inspector. I bought a new travel trailer last year that required 80 PSI. The gauge I had didn’t go that high and I knew it was off 2 PSI when comparing to my cars readings. They tell me the tire pressure monitors in cars are accurate. Bought what I thought was a good analog gauge. It didn’t seem to work right. Bought a large pencil type gauge from NAPA thats claims/states it’s use is also to check other tire pressure gauges. Now this gauge seems to at least work. The new RV’s use nitrogen (green cap) instead of air. I had trouble putting air in the tire and getting the tire pressure gauge to read the pressure. Showed the RV dealer something red in the valve stem. He told me to pull it out and discard. It was a red o-ring. Now I have no trouble putting air in or checking tire pressure. Hope this helps.

Bob p
8 months ago
Reply to  Bob M

Gee are you aware that the air you and I breathe is 78% nitrogen, 21% oxygen and 1 % inert gas. Nitrogen filled tires is one of the latest scams, unless you’re racing, flying your vehicle several thousand feet in the air where pressures change by altitude, you don’t need nitrogen in your tires.

7 months ago
Reply to  Bob p

Tire pressure doesn’t change with altitude, but gauges do unless you have one that adjust to altitude. $150

1 year ago

Unless I missed it this article is about buying a good pressure gauge yet not one is listed. I have looked at many different gauges at many different prices and still don’t know what makes them good or bad

1 year ago
Reply to  Scott

Amflo and Milton. I sold hundreds of them before I retired. You might consider buying two of them in order to check one against the other, as they are not that expensive. Also, dont assume that the guy working in a tire shop is using a good tire gauge. Most likely he has to buy his own gauge. Most people will spring for a quality tool but too often new employees start in tire shops as “tire busters” and cannot or will not buy a decent gauge. Shops usually dont provide any hand tools because they get lost, abused, etc. The same goes for torque wrenches, and believe me, you want your wheels torqued to manufacturers specs. In short, unless you are familiar with a shop it is a crap shoot, so just buy two quality gauges and check your tires yourself.

7 months ago
Reply to  Scott

Truck stops usually have the best selection.I prefer the Milton brand.

Roger Marble
7 months ago
Reply to  Scott

I have found Accutire digital gauges accurate to +/- 1.0 or better. I have checked mine against an ISO laboratory master gauge and all three were within +/- 0.5 psi of the master. For regular use I would feel OK with +/- 2 psi if you read to the 1 psi level. I do not like gauges that only read in 5 psi increments.

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