Tire gauges
Everyone talks about tire pressure but just how accurate are those gauges you use to measure tire pressure. I started out with a collection of 38 tire gauges (loaned to me)
Various sizes and shapes, some new and some very old. Also we tested some digital
gauges some cheap the others expensive. Our test was conducted at our aircraft maintenance shop and against a highly accurate calibrated air pressure standard. I took each gauge and measured three air pressures consisting of 25, 35 and 45 lbs.
All the testing is done and the results in Parts will be published at various times.
Part one consisted of the most popular tire gauge called the pocket or pen type gauge which cost anywhere from $ 1.00 to $ 2.50 range and they have a white plastic dial reading. I tested 5 new ones (Victor, Monkey Grip etc) that were purchased at nationwide chain and auto stores. Each of the new ones read entirely different pressures with the worst being as much as 6 lbs. lower at 25 lbs. While an exact duplicate gauge read 3lbs. lower at 25 lbs. The new ones where mostly 3 lbs lower at 25lbs but improved at the higher pressures of 35 and 45 lbs. There averages where about 2 lbs. at the higher pressures. I tried exercising the dial a few times by pulling it in and out and taking the readings again and some improved by as much as a lb. at the lower reading. I then test older gauges of this type 3 to 10 years and the results were worse in some cases. It seams the older the gauge the lower the accuracy and they are the worst at the lower pressure. Some were off as much as 8 lbs. By the way all of the gauges we tested read low except one and that had an obvious defect. I took the older gauges and sprayed the dial with WD-40 and exercised it about 10 times and then I went back and redid the test and improved the readings to that of a new gauge. One gauge was 7 lbs lower at 35lbs and after my operation the gauge improved to about 2.5 lbs lower. One gauge that was 10 years old had better accuracy than one that was 3 years old, but generally the older the gauge, the lower the accuracy of gauges of this type. You get what you pay for.
In conclusion. If you want 30 lbs put in the air till your pen type gauge reads 28 lbs. and don't forget to exercise the dial a few times before checking the tire pressure. On the older ones spray the dial with WD-40 or some silicone lube and exercise the dial about 10 times. The average after we got them working was about 2 lbs. low Part 2 deals with more expensive gauges with some surprising results until then-by
DCH
Various sizes and shapes, some new and some very old. Also we tested some digital
gauges some cheap the others expensive. Our test was conducted at our aircraft maintenance shop and against a highly accurate calibrated air pressure standard. I took each gauge and measured three air pressures consisting of 25, 35 and 45 lbs.
All the testing is done and the results in Parts will be published at various times.
Part one consisted of the most popular tire gauge called the pocket or pen type gauge which cost anywhere from $ 1.00 to $ 2.50 range and they have a white plastic dial reading. I tested 5 new ones (Victor, Monkey Grip etc) that were purchased at nationwide chain and auto stores. Each of the new ones read entirely different pressures with the worst being as much as 6 lbs. lower at 25 lbs. While an exact duplicate gauge read 3lbs. lower at 25 lbs. The new ones where mostly 3 lbs lower at 25lbs but improved at the higher pressures of 35 and 45 lbs. There averages where about 2 lbs. at the higher pressures. I tried exercising the dial a few times by pulling it in and out and taking the readings again and some improved by as much as a lb. at the lower reading. I then test older gauges of this type 3 to 10 years and the results were worse in some cases. It seams the older the gauge the lower the accuracy and they are the worst at the lower pressure. Some were off as much as 8 lbs. By the way all of the gauges we tested read low except one and that had an obvious defect. I took the older gauges and sprayed the dial with WD-40 and exercised it about 10 times and then I went back and redid the test and improved the readings to that of a new gauge. One gauge was 7 lbs lower at 35lbs and after my operation the gauge improved to about 2.5 lbs lower. One gauge that was 10 years old had better accuracy than one that was 3 years old, but generally the older the gauge, the lower the accuracy of gauges of this type. You get what you pay for.
In conclusion. If you want 30 lbs put in the air till your pen type gauge reads 28 lbs. and don't forget to exercise the dial a few times before checking the tire pressure. On the older ones spray the dial with WD-40 or some silicone lube and exercise the dial about 10 times. The average after we got them working was about 2 lbs. low Part 2 deals with more expensive gauges with some surprising results until then-by
DCH
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Drew
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DCH
The results show once again you get what you pay for. These types of meters showed pretty good accuracy over the ranges and age didn't seem to slow them down on the lower range.
Part 3 which consist of Digital Gauges will follow soon. One tested so accurate, I went out and bought one and tested it for repeatability and it indicated the same as the first. Which one was it? Stay tuned Until then---by
DCH
DCH
Thanks for the great reports. I have the Accutire $14.95 digital guage and now know I am getting "true readings".
Thanks Again,
Tron
The increasing number of safety warnings on products continues to amaze me. Has anyone ever even heard of any real accidents involving tire gauges? I used it today, and blatantly risked bodily harm by going without goggles.
guard and a groin protector just in case the
gauge would do something funny
greg
I am worried that I might have mis-aligned my wheel. Would anyone know, if I did (aside from getting symptoms on my tire later on or going for an expensive wheel alignment check?
Oh.. I do prefer the digital better even though the pencil is almost as accurate since the digital is within .5 psi. The battery of the digital should last for thousand of uses.... I won't be around to verify that though.
I'll stick with the metal cased old style gauges.
As for battery in a digital gauge, the one that I have said "You observe "L" on the display. the power supply has been depleted. Return to factory for free replacement...." anywway, I am sure that they set it to stop measuring when the battery is too low. Observe the same behavior in your cordless phone or whatever....
The 4000 works very well for me. It has a digital readout that shows 1/2 lb increments.
Features:
* Latest technology in digital air-pressure measurement delivers precision accuracy
* Large backlit LCD display lights up for nighttime viewing
* Accurately measures 5 to 99 psi in 1/2-pound increments
* Runs off a Lifetime Lithium battery and automatically shuts off
* 5 year warranty
The battery is meant to last a "lifetime", and the gauge is guaranteed for 5 years against defects in manufacture.
Lifetime generally means the life of the product, not the person who bought it. Hence if the warranty is 5 years the product life is 5 years. Of course the battery will probably last much longer than that - you just won't get a free one when it dies.
1. Accutire MS-4000
$30
Digital
5-99 psi
2. Accutire MS-4020B
15
Digital
5-150 psi
3. Monkey Grip M8867
10
Digital
5-99 psi
4. NAPA 90-389
8.50
Pencil
10-50 psi
5. Monkey Grip M8862
3
Pencil
10-50 psi
6. Pressure Inc. DT-105
11
Digital
1-100 psi
7. AccuGauge H100X
19
Dial
5-100 psi
8. Monkey Grip M8854
9
Dial
2-60 psi
Hmmm... I wonder if I could convince the wife the new valve stems were needed for the new tire gauge and the new stems were already installed in the new tires and the new tires were already on the new car.....
Ahhhh, common sense. Far too often we get hung up on things. My dad used to think that if he paid the highest price, he got the best quality - and he was a businessman. When he traded cars at his favorite dealer, the dealer would quote a price, Dad would come back with "That's too high, Paul, sharpen your pencil. Paul would then lower his price and my dad thought he was really dealing. The fact is, Paul knew the game and started out high. When he 'sharpened his pencel', what he really did was to drop it to what he really wanted for the car. Buyer beware. In all fairness, the tools we have today to research weren't available then.
Take the time to understand the product and the deal, then apply common sense and see if paying for the high priced spread is really worth it. Some can't settle for anything else, and that's fine, if after going through the process, they still want to spend the bucks.
"My lifetime? The lifetime of the gauge? How about if I were to give the guage to my son? These things aren't registered, so they can't control such "transfers". Also, do they replace the battery for you, or give you a new gauge? "
The devil is in the details. My wife just paid $300 for a landscape 'plan' which with be returned if we buy product. Sounds simple, right? She asked no further questions. My questions were: 1. Can you just buy $300 worth of plants at no charge beyond the plan cost? 2. If not, how much must you buy to get the 300 credit? 3. Must you pay for the entire plan before you receive the credit? To me, important questions. Never occured to her. Try as I may, I can't get her to think beyond the first thing.
Very Accurate Digital Tire Pressure Gauge
0-90psi
0.25% accuracy
0.1psi display increments (must have this)
12-18" rubber hose
Similar to the following, but not so expensive
http://www.buxtonengineering.com/digital_tire_pressure_gauge.htm
http://www.intercomp-racing.com/detail.cfm?ItemID=60
Meets all your requirements, except that it's 0-50psi, not 0-90psi.