how accurate are inexpensive tire pressure guages?

[tonycarguy]

Do you guys use the $2 pencil gauges, $5 "clock" gauges, or some $30+ high end one?

I knew a guy whose tires had symptoms of overinflation (ie, excess wear along the center) even though he supposedly inflated the tires to the correct pressure. This sounds like an inaccurate gauge.

Can an inexpensive gauge be trusted?

 

[Corvette Owner]

I use the $8-10 digital kind. They are VERY accurate, always the same as my expensive Corvette Tire Pressure Measurement Sensors (TPMSs).

 

[John_K]

I have found the cheapie ones inaccurate.

John

 

[IndyIan]

I have 3 of the pencil gauges, they seem to be within 2-3 psi of each other. Close enough for me.
Don't trust the gas station pump gauge though, they get dropped 1000's of times...

 

[chrome]

I have a cheap $10 digital gauge from ebay, and a nice German-made dial type gauge. They are both very close (~1 psi difference).

Your friend with the overinflated tires may be relying solely on the pump gauge which are often inaccurate. I have seen such gauges cause over-inflation by 20 psi.

 

[55Test]

I use the cheap pencil looking ones. Every one I've ever used has always been within 2 PSI of accuracy. One time I had one of those 'clock' dial gauges and it was about 15 PSI off. No wonder my cars always rode so [censored] hard while I was using it.

 

[tonycarguy]

I used to use a $5 dial gauge, but it broke recently. I have no way of knowing how accurate it was. But I know that the gauges that come attached to $20 pumps are waaaay off.

 

[mrsilv04]

When I have a motorcycle tire mounted, the mechanic always leaves it at 40 psi.

Then, when I get home, I check all of my gauges against the 40 psi in the tire.

How do I know that his gauge is accurate? He races motorcycles for a living. I'm sure his high dollar gauges are plenty accurate.

 

[dwendt44]

http://www.getagauge.com/DialTireGauges.cfm

 

[huffmuds9320]

I have a digital tire gauge (~$8) and a Milton pencil tire gauge ($5). The pencil gauge reads 2psi higher than the digital gauge, the Milton gauges are made in USA. I had a few pencil gauges I got for free at fairs and stuff, those were very inaccurate giving inconsistent readings, not a good way to promote properly checking the tire pressure. Dial gauges from what I hear is more accurate if the reading falls in the middle portion of the gauge. Therefore a 0-60psi range would likely be a better choice than a gauge with 0-150psi range for most passenger cars.

Motorcycle Consumer News has a article testing various pencil, tire and dial gauges. Click the "Tire Pressure Gauges" link, it is a pdf document.
http://www.mcnews.com/mcn/technical.asp

 

[Vikas]

I recall an advertisement for a dial gauge which had inlet for filling the air. This allowed you to measure the tire pressure *while* still connected to air pump. That seems to be very good idea. I don't remember where I found that ad though.

- Vikas

 

[Eddie]

CU did some testing on tire pressure gauges. Maybe someone can remember the date of that isssue. I use a $10 digital from Sears that reads to 0.5 psi. Nice and handy and has lasted for 4 years without needing a battery. The gauge also allows one to read the gauge in the dark or very dim light which is a plus for me.

 

[eljefino]

My dad had an extra schraeder valve on his cheezy cigarette lighter inflator. It read several pounds over the tire pressure as it was inflating. (why didn't they just put a (bad) gauge in instead?) I assume there was a restriction further down the line from the compressor.

I have a "brookstone" dial gauge with a rubber protector that got dropped and knocked out of whack. It's still fairly accurate/repeatable if you apply a 15 PSI bias.

They say these types are easiest to foul up by dropping/abusing if you toss them around like most other tools.

My peeve is the little rubber gasket on the tip; it wears out or doesn't fit right and one vents lots of air trying to get a reading.

Consumer Reports actually had to recall its own promotional tire pressure pencil gauge because it wasn't accurate.

 

[PT1]

I got a nice digital one from my inlaws for Christmas last year. Aside from allowing me to ravage their daughter

for the past 22 years...it is the nicest thing they have done for me.

 

[tonycarguy]

Yes those dial gauges with a large range like 0-150psi are inaccurate. That's why those el cheap pumps have awful gauges -- they're usually 0-150 psi.

 

[ARCOgraphite]

You have to check the gauge against a calibrated standard. Good luck finding a pressure vessle with a schraeder valve and a recently calibrated gauge on it! A good pencil gauge works well for me - the dial gauges always get broken too soon. (Digital does nothing to improve the accuracy - unless you get a NIST tracable Certificate of calibration with the unit, it prob no better than 2-5% of range.

 

[ARB1977]

Ive got an analog type along with a tire gauge for my air compressor...haven compaired the two, maybe i should.

 

[eljefino]

Originally Posted By: PT1
I got a nice digital one from my inlaws for Christmas last year. Aside from allowing me to ravage their daughter

for the past 22 years...it is the nicest thing they have done for me.


They make a great gift for under $20 for the car lover who probably already has one!!

 

[rationull]

I have a cheap dial gauge that goes up to 60 PSI, a pencil type that goes up to 100 PSI or something, and a 12 volt compressor with a dial that goes up to 150. They all agree within 1-2 PSI .. good enough for me.

 

[dwendt44]

The greater the range of the gauge, the larger the actual error is.
It's a percentage of a larger amount.
+/- 2% of 150 lbs. is more that +/-2% of 50 lbs.
In other words, a 0-50 lb gauge is all most of us will ever need.