Tire Pressure Gauges- Pressure Varies!

[Ray Eklund]

I have always used the "stick" pressure gauge to check my tire pressures. I also noticed that from the two stick gauges used, they would indicate different pressures from the same tire. They also would vary, depending on temperature that affected the center stick with the readings. The tire service would use their "sticks" and have a different pressure... what to do, what to do!!?

Welcome Digital AGE! I have a Craftsman (from Sears) and a Accutire (from Costco) digital readout gauges for a year. These seem to be much closer to being... accurate. Several days ago I had the Tundra's oil changed at the dealership and they checked tire pressures... each had 40psi. Well here are the results at home. The first tire on each guage is the same tire, 1, 2, 3 and 4.

Accutire: 42.1psi, 42.2psi, 42.3psi, 43.2psi
Craftsman: 42.5psi, 42.5psi, 42.5psi, 43.5psi

I will keep the Craftsman in the Tundra as I use it to tow the 23 foot Safari. At least the pressures seemed steady. Although both were pretty close, you can get different readings. The fourth tire and the 43.5psi I retested several times to get 43.5psi.

The Accutire is easier to use than the Craftsman, due to the straight testing position and fits into your palm for a firm fit. The Craftsman is at a 80 degree angle, or so, and sometimes you need several attempts to get a firm fit.

Anybody have a brand of pressure gauge that has worked out well?

To add... I use to sell antique coin operated games and equipment. One sale was a 1930's Mills penny floor scale. One sold to an Advertising Agency and a week later the owner calls and said my scale was not accurate. I asked how did he know? It varied from his home scale. I asked, how did he know his home scale was more accurate than the floor scale? That settled the question, but I told him that the penny floor scales were not intended to be accurate, but close. It is the relative weight each day from the same scale that is important. A doctor's office with an accurate scale can then varify if you need to make the mental adjustments... Depending on how accurate to actual tire pressure your gauge measures, could explain some problems with tires descibed on the forum.

[Inland RV Center, In]

Originally Posted by Ray Eklund

I have always used the "stick" pressure gauge to check my tire pressures. I also noticed that from the two stick gauges used, they would indicate different pressures from the same tire. They also would vary, depending on temperature that affected the center stick with the readings. The tire service would use their "sticks" and have a different pressure... what to do, what to do!!?

Welcome Digital AGE! I have a Craftsman (from Sears) and a Accutire (from Costco) digital readout gauges for a year. These seem to be much closer to being... accurate. Several days ago I had the Tundra's oil changed at the dealership and they checked tire pressures... each had 40psi. Well here are the results at home. The first tire on each guage is the same tire, 1, 2, 3 and 4.

Accutire: 42.1psi, 42.2psi, 42.3psi, 43.2psi
Craftsman: 42.5psi, 42.5psi, 42.5psi, 43.5psi

I will keep the Craftsman in the Tundra as I use it to tow the 23 foot Safari. At least the pressures seemed steady. Although both were pretty close, you can get different readings. The fourth tire and the 43.5psi I retested several times to get 43.5psi.

The Accutire is easier to use than the Craftsman, due to the straight testing position and fits into your palm for a firm fit. The Craftsman is at a 80 degree angle, or so, and sometimes you need several attempts to get a firm fit.

Anybody have a brand of pressure gauge that has worked out well?

To add... I use to sell antique coin operated games and equipment. One sale was a 1930's Mills penny floor scale. One sold to an Advertising Agency and a week later the owner calls and said my scale was not accurate. I asked how did he know? It varied from his home scale. I asked, how did he know his home scale was more accurate than the floor scale? That settled the question, but I told him that the penny floor scales were not intended to be accurate, but close. It is the relative weight each day from the same scale that is important. A doctor's office with an accurate scale can then varify if you need to make the mental adjustments... Depending on how accurate to actual tire pressure your gauge measures, could explain some problems with tires descibed on the forum.

Tire pressure, after a few miles, can change differently.

If they are not "ALL" balanced correctly, then one, or more that is not, will bounce when in motion.

That in itself, will cause a tire to heat up moreso than one that is properly balanced, yet will return to proper pressure, once it cools down.

Andy

[Ray Eklund]

Hi Andy,
I had the oil and filter changed on the 3rd of July and the tires would have been hotter driving to the dealership. My readings are today, July 5th, and are cold tire temperatures. Even though one side of the truck had the sun exposure and the other, not. I would suspect that even that could affect pressure differences.

When I have a cold temperature reading where all tires agree, I would also expect the tires when hot to be close as well, yet higher. Since I am not doing a Consumer Reports trial, I thought this would be a chronic problem when you are taking a tire pressure and no two gauges agree as to the true tire pressure.

[azflycaster]

I use the accutire that I bought at Costco. It is very easy to read and gives me the same numbers as the slide type that is on my compressor hose.

Many things can effect the pressure of the tires. Altitude, temperture and even load on the viechle are all factors. The biggest problem I have is checking the tires when they are cold. It hasn't been cold in Phoenix for months.

[richinny]

Originally Posted by azflycaster

It hasn't been cold in Phoenix for months.

you missed your chance on 6/1 ;-)


http://www.airforums.com/forums/569637-post151.html

[azflycaster]

Originally Posted by richinny

you missed your chance on 6/1 ;-)


http://www.airforums.com/forums/569637-post151.html

You make a good point, except:
It was not in Phoenix and I could not find the tires...

[overlander63]

Most tire gauges are supposed to be accurate within 1 PSI. In most tire shops, all tire gauges are supposed to be checked for accuracy to a master gauge that has been calibrated. In the real world, of course, it doesn't happen. Just remember that a tire gauge is supposed to give you an idea of how much pressure is in your tires. I have a tire inflator/gauge that is 1 psi low, and another that is 10 psi high.

[Mikethefixit]

I have two long truck gauges Ive had for a while. I used them when I had my big trucks. I still use them today. They are within 1 lb of each other I also have an analog Airing Device and I check against them. If your tires are within one lb of each other and are at what is listed on the tire. NOT TO WORRY. Your GOOD

[Cracker]

Unfortunately, I've thrown away a good number of gauges - and taken several back to the auto parts store because they wouldn't give the same reading, on the same tire, twice in a row! The gauge I use now, for the AS and the dually, cost $36.00, or thereabouts, and it has always been accurate. It is a high pressure gauge (truck type) and it has the bi-directional angled head necessary for dual tires. Apparently higher cost does buy higher quality! I have also found two other low-pressure gauges that have proven to be accurate over time - and I keep one in each of my small cars. With several of the cheaper gauges I could get a substantial difference in the reading depending on the angle of the gauge when it was placed on the tire stem. I'm a tad anal about tire pressures - especially for the duals - normally maintaining the pressure within a one-half pound margin

[2dabeach]

Ray

When I purchased my GMC truck I had to upgrade my tire pressure gauge to be able to read up to 80 psi. I purchased an Accu-Gage, dial-type, pressure gauge that reads to 100 psi. The gauge is distributed by G. H. Meiser & Co and is assembled and tested in the USA and comes with a lifetime warranty. You can add a rubber gauge guard and vinyl pouch for a few extra dollars.. I use it to fill the tires and then monitor the tire pressures with the Pressure Pro monitoring system. The Accu-Gage is very accurate and is verified with the Pressure Pro readings. When parked you will see a difference in individual tire pressures as the sun starts to shine on each of your tires. You will also see a large drop in pressure when you hit some low temperatures when your traveling.

[Rebee]

In the paper work that came with your gage. what was the accuracy of the indicator? 10 %, 5%? In either case the gage probable meets specs.
If my tires are within 2 lbs/sq in I am satisfied.

[2dabeach]

Originally Posted by Rebee

In the paper work that came with your gage. what was the accuracy of the indicator? 10 %, 5%? In either case the gage probable meets specs.
If my tires are within 2 lbs/sq in I am satisfied.

Rebee

The literature that came with the gauge and their website did not list the accuracy of the gauge. The paperwork indicates that it was tested for accuracy before shipment and that the bronze Bourdon tube movement is not affected by changes in temperature, humitity or altitude. You can check with them at Accu-Gage Tire Gauges

[azflycaster]

My accutire is rated at +/- 1% +0.1 PSI. I know what the +/- 1% is, but what is the + 0.1 PSI mean?

[markdoane]

When the accuracy is given as +/- 1%, usually it is the percent of full scale. If the gauge is good for 100 psi, that would be 1.0 psi. Then you add 0.1 psi to that value and the accuracy is +/- 1.1 psi

[HiHoAgRV]

Originally Posted by overlander63

Most tire gauges are supposed to be accurate within 1 PSI. In most tire shops, all tire gauges are supposed to be checked for accuracy to a master gauge that has been calibrated. In the real world, of course, it doesn't happen. Just remember that a tire gauge is supposed to give you an idea of how much pressure is in your tires. I have a tire inflator/gauge that is 1 psi low, and another that is 10 psi high.

We used a gauge that was very repeatable, but off by 4 psi years ago when kart racing. It gave us an advantage when our competitors borrowed it...

We did check its repeatability on a regular basis.

[rodsterinfl]

Anybody have a brand of pressure gauge that has worked out well?

Hello, hindsight here! I bought one of the Longacre Pro Racing Gauges for a lifetime of service:

It has a guaranteed accuracy of 0.2 lbs to 60 psi. Then accuracy falls gradually to 0.5@150 psi. That said, every time I go to use it, the battery is dead. I would be willing to go with an accurate gauge style. I really like digital but not battery replacement.

[wimpy]

In the early 80's when I was in the tire business, everyone accepted the stick gauges (single or dual-foot) weren't as accurate as they should be. Drop one and you could count on it being off. The round analog gauge was the only thing we ever used at the racetrack & took very good care of them.

With the advent of digital gauges that has definitely improved repeatability & reliability but you still need to take good care of them.

More expensive is better, IMHO.

[Rich W]

Wow, a pretty old thread but still pertinent. I got an Intercomp INT-360078 Air Gauge 0-100 x 1 psi - 4" Glow-in-The-Dark Dial on Amazon. I've been very pleased with its performance. The big dial makes it much easier to read than the stick type gauge.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Wconley]

I used to race cars and we would adjust each tire’s pressure to within 1 PSI for different tracks and road conditions (sun/cloudy/rain, etc). We always used Longacre dial gauges which is what I use for our trailer pressures. For awhile I used a no-name brand gauge that was accurate compared to the Longacre at first and until one summer it slowly fell out of calibration.

Occasionally I check the Longacre against a local tire store gauge. Interestingly enough, our EEZTire monitor is accurate to the Longacre +/- 1 or 2 PSI except one sensor that sometimes will be consistently about 5PSI low for a day and then back on track.

[JonDNC]

Originally Posted by rodsterinfl

Hello, hindsight here! I bought one of the Longacre Pro Racing Gauges for a lifetime of service:

It has a guaranteed accuracy of 0.2 lbs to 60 psi. Then accuracy falls gradually to 0.5@150 psi. That said, every time I go to use it, the battery is dead. I would be willing to go with an accurate gauge style. I really like digital but not battery replacement.

This is what I use, not had a battery issue yet..