tire pressure gauge accuracy

[huffmuds9320]

I find the best time to check tire pressure is in the morning. Some gauges tell you on the back the packaging like +/- 0.5psi something like that. The $300 digital one looks nice a bit too expensive for personal use.

I noticed that most tire pressure gauges have the head at an angle. Rarely do I see the kind that is straight. Is there a big difference there?

 

[Kestas]

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... I wonder if the tires facing the sun will read differently than the other side that's in the shade?

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No need to wonder. I've often checked tire pressures when one side is in the sun. I've seen 2-3 psi difference between sun and shade.

 

[BMWR1150GS]

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Lon, that can make a bigger difference than many people might believe. I've seen differences of 4 & 5 psi on my own cars in extreme circumstances.

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Correct. And, this can lead one to overinflate the cooler tires or bleed air for those that are in the sun.

I have a motorhome that carries 95 PSI in the rear duals. I must be careful not to upset cold tire pressures on the sunny side pair when cold checking. The outside tire may have been heated by the sun with several PSI offset resulting. I try to cold check before the sun has had time to heat the exposed tires.

 

[y_p_w]

Be careful if you drop a dial gauge. I Dropped an Accu-Gage once and the results went way off. I found out they actually offer a rubber sheath to reduce problems if it's dropped or to reduce shock from rough handling.

 

[Drew99GT]

Engine heat can give your front tires an additional 2 or 3 psi as well.

I've dropped so many $15 quality dial gauges, I'm sticking with digital!

 

[PandaBear]

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I must disagree there. If a gauge is imprecise, it is also inconsistent from measurement to measurement.

I can definitely tell a difference of two pounds between two tires opposite on the same "axle": the car wants to wander to one side. Subjectively, I think the threshhold is close to, but slightly less than, a pound. If my tires opposite each other differ by a pound, I am fairly (but not 100 percent) certain that I do feel the difference through the steering wheel. With 0.5 pound accuracy, I am certain I cannot tell the difference through the steering wheel. In any event, two pounds is too gross.

Of course, if a gauge is very precise but also very inaccurate (that is, it consistently reads 45 +/- 0.5 pound pounds when the actual reading should be 30 pounds), we both could be right, but I do not think such a scenario is realistic.

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This is the difference between repeatability vs. precision. You should definitely throw away low repeatability gauge, but low precision one, if you know how much it is off by, are still usable.

I know the one on my craftsman tire pump is 5 psi off, talking about way off to lunch.

 

[Jonny Z]

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I was wondering which type of tire pressure gauge is considered to be the more accurate one.

Are digital tire pressure gauges the most accurate? I was considering getting one at Kragen, ~$12-15. Any comments thanks.

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Digital tire gauges generally are more accurate and less subject to damage from jarring, etc., than analogue tire gauges.

Just as important, however, is mating the gauge chuck to the tire valve. The ubiquitous Accutire gauges (identical but for packaging units are sold as Monkey Grip and Ace Hardware gauges) are notorious for being difficult to obtain a repeatable non-leaking connection to the tire valve. Bottom line: the one you want is this: Campbell-Hausfeld digital gauge. The Campbell-Hausfeld model AU1102, which is sporadically available, is even better (for having a cast zinc, instead of plastic, body).

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I have the AU1102. Paid about $10 at Wal Mart. Two problems - the first read is always 3-4 PSI too high, the second read on will agree with each other. The ID of the chuck is too narrow and has some casting defects, it rubbed against the valve stems and caused some damages to the threads.

 

[Jonny Z]

BTW, I have yet to find a gauge that works better than my Victor dial with a bleed valve on it.

 

[Cruncher]

Check out the line by Intercomp.

 

[unDummy]

I have several GH-Meiser dial gauges. Excellent and can be sent back for repair/calibration for a couple bucks. A bunch of brands are also rebranded GH gauges. I also always buy the rubber protector for my dial gauges.

I also don't care for reviews. Simply dropping a gauge can knock its accuracy out. And, if you live in a hot area, any of the digital gauges can be cooked inside your vehicle.

 

[Carmudgeon]

I've been using the same Accutire digital gauge I bought at Costco back in the late 80's.

I compared it to a couple mechanical gauges I have, and all three presented the same readings.

It was cheap, drop-resistant, and I wouldn't fret if it was lost or stolen. I know of one that was run over and still functions. Like any good tool, a faithful servant that works.

Recently, I was looking for a gauge with a hose to deal with a difficult stem, and found that the GH-M gauges are now made overseas. Are they of the same quality as the older US-made gauges?

 

[RacerE7773]

I have a pencil type in my cav. and digital in my wife's car. As she isn't able to decipher the lines and such. Though the digital is made in China, still a decent gauge. Though I think for similar I'll go to Advance instead of Napa from now on ($21 almost after tax.)