Tire gauges

dchoppdchopp Posts: 256
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
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Comments

  • drew_drew_ Posts: 3,382
    Thanks DCH! Great new topic to start. I have renamed it to "Tire gauges" so that we can discuss anything about tire gauges in this discussion topic, including your posts As mentioned, I look forward to reading the rest of your research!


    Drew
    Host
    Vans, SUVs, and Aftermarket & Accessories message boards
  • tronsr1tronsr1 Posts: 149
    I just received a digital tire guage for a birhtday present {it was purchased at Radio Shack} and I am anxious to get your digital read-out results. I keep 29 lbs. in my 2001 Ford Escape {as per recommended on the door} and find the digital guage very easy to use and also very easy to "read'.
  • dchoppdchopp Posts: 256
    The digital gauges I tested where very accurate over the range, however I found two that where off by as much as 4lbs. at 35 lbs. the owners brought in the directions and it required a self calibration check prior to using. After we did it the accuracy improved to about a 1.5 lbs. So read your directions and see if it requires a self calibration prior to using.
    DCH
  • tronsr1tronsr1 Posts: 149
    O.K. Will check directions as per above post. Thanks for the input.
  • Does anybody have any good recommendations for brands/models of digital gauges? How about info on price and accuracy?
  • sirfilesirfile Posts: 42
    Accutire makes an excellent digital gauge that is easy to use and has a large readout in .5 pound increments from 5-99 pounds. The gauge is recommended by The Tire Rack, and through www.HerringtonCatalog.com for $29.95. I also saw it advertised at Sears today, for only $13.95. It makes a great gift for others [or for yourself]. Be sure to check your tires once a week when the tires are cold.
  • dchoppdchopp Posts: 256
    Tire Gauge Accuracy Part 2. In Part 1, we did an evaluation of the cheaper pocket or pen type gauges. Part 2 consist of the more expensive heavy-duty double-headed type of gauge. Price range is in the $5.50 to $13.00 range. Basically the same names as indicated in Part 1 and a few new ones like ACCU. Most were purchased at local retail and automotive stores such as Napa ,Advance etc. We also tested some Analog or dial type of a gauge. Since these gauges cost more, we expected more from them and they didn't disappoint us. Since these gauges have a much larger range than the cheaper pocket type, we had to expand our testing to the 100lb. range. These gauges were tested at 25,35,45, (lower range) 60, 75, and 90 lb. range, which we called the upper range. Some where brand new, some where old like over 10 years. The gauges with the metal type indicators read about 1 to 2lbs long over the short range and about 1 lb. long on the higher range. Long means that for a known source of air pressure 35lbs. these gauges were indicating 36 or 37 lbs. Exercising the indicators did nothing to improve the accuracy. As these gauges start to get old (6 years and above) they tend to get a little sloppy on the higher end indicating as much as 3 to 5 lbs. higher. The shorter range still remained accurate within 2lbs. The newer type replaces the metal indicator with that of a white plastic dial much like the cheaper pen or pocket type. Easier to read I guess. These type of gauges read differently over the ranges, much like the cheaper ones. On the short range these gauges indicated about 1 to 2lbs. short. So for 35lbs. they would indicate 33 to 34 lbs. On the upper range they were very inconsistent with some reading 1 lb. short while others reading 1 to 2 lbs long, while down in the lower range they were all short. Exercising the indicators a few times improved some in the upper range but not in the lower range. Still overall the accuracy over both ranges was very good. The analog or meter type of gauges were very inconsistent but accurate. Some were short while some were long over the ranges and the brand didn't seam to matter. Two identical read differently. The 8 we tested were within 2 lbs in both the lower and upper ranges. Just remember to check to make sure the gauge reads zero before checking air pressure. Most come with an adjusting screw to do this. I dropped one on the floor and it indicated about 3lbs long. When in the first test, it indicated 1lb short over the ranges. After I zeroed the meter, it was ok. One analog type was reading all over the place as much as 8 lbs off. Here the meter had a static charge on the meter face. I rubbed a little Wd-40 on the meter face and it was ok after that.
    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
  • tronsr1tronsr1 Posts: 149
    Keep up the good work. Your posts are very informative.I am still using my digital guage from Radio Shack and eagerly awaiting the results of your tests.
  • mrdetailermrdetailer Posts: 1,118
    Your research is impressive. Looking forward to your next report.
  • dchoppdchopp Posts: 256
    Tire gauge accuracy Part 3. The final report deals with the accuracy of Digital Gauges. We only had 8 gauges to test in this series, since most people use the gauges we tested in Parts 1and 2. Some of the brands we tested were Victor, Accutire, Majestic, and MG. Since these gauges had indicators up to 100lbs and more we tested them at 25, 35,45,and 50 lbs., which we called the low range. The high range indication consisted of measurements of 60,70, 85 and 100 lbs. All of the digital gauges tested were very accurate over both ranges. We caution you to read your directions carefully, since some of the gages required a self-calibration prior to using. If you don't calibrate them your reading can be off as much as 5 lbs on the lower ranges. The $6.00 gauges we tested were off only 1.5 lbs on the short range and about 2 lbs on the higher range usually 85 lbs. and up. The more expensive Gauges such as Accutire tested the best. The $14.95 gauge tested 0.5 lbs long on the low range and 1lb. long on the higher range. We tested the Accutire lighted background model $30.00 and it read perfectly in the low and higher ranges. It was off by 0.5 lbs (short) at 100 lbs. Every other pressure I tested it at read the correct pressure. I went out and bought one (Sears) and tested it for repeatability and it tested the same. Overall these gauges were very accurate and some do require a self calibration. They were all very easy to read. In time I feel more people will buy them. This concludes my report and I hope it was helpful.
    DCH
  • tronsr1tronsr1 Posts: 149
    dchopp,
    Thanks for the great reports. I have the Accutire $14.95 digital guage and now know I am getting "true readings".
    Thanks Again,
    Tron
  • mrdetailermrdetailer Posts: 1,118
    Thanks for all of the careful research dchopp.
  • Thanks for analyzing the gauges. I hope you had free access to all the models and did not have to purchase them.
  • lovable90lovable90 Posts: 27
    Thanks, Dchopp for doing all that research. I read your posts yesterday and went out and purchased an Accutire digital gauge today. This model has an indicator up to 150lbs and may require a self-calibration. The original price was $14.95, but Sears had it on sale for $7.99! Such a deal!!
  • mrdetailermrdetailer Posts: 1,118
    adn really enjoyed it. However, I found that all of my low cost gagues are just about as accurate. At least I know I won't have to tote the expensive gauge on vacations.
  • Thanks for the report,dchopp. I bought the Accutire 150lb model today . My old dial gauge is 4.5 lb high (i.e. reads 35 lb when it reads 30.5 on the Accutire)
  • I just bought a new gauge today (dial-type) and noticed a warning about needing safety goggles on the back of the package:

    image

    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. :)
  • cyranno99cyranno99 Posts: 419
    maybe it is a really cheap gauge and will shot to your face like a rocket when you attach it to the valve of the tire :) They must be really afraid of being sued.
  • dchoppdchopp Posts: 256
    You didn't wear goggles to check your tires with this guage. Shame on you. If you read the fine print it probably tells you to wear protective clothing also.
  • barnonebarnone Posts: 118
    the warning label should include wearing a mouth
    guard and a groin protector just in case the
    gauge would do something funny :)
  • morin2morin2 Posts: 399
    My trusty old Brookstone dial guage just turned 25, given to me by my wife in 1976. Made in USA & used every weekend since new. Just bought 2 new Brookstone tire guages which are now rubber-coated but still made in US, for gifts. Checked the new ones against the 25 year old model on a tire & reading was the same for all 3. Cost is now $10 each.
  • nygregnygreg Posts: 1,936
    I want to thank you for great information in a controlled test. I just happen to have purchased 2 of the Accutire gauges at Sears for $8.99 ea (on sale) about a month ago. After calibrating, they read about 0.5 lbs within each other. Funny thing, my old pen "pop up" type gave me the same reading as the Accutire. Still, I trust the digital more. Again, thanks.

    greg
  • pblevinepblevine Posts: 858
    But I didn't see this topic until now. I had gone out and purchased a very rugged analog gauge made by "Meiser". Its solid brass covered in rubber and has a short hose attached for pushing against the tire valve. It seems to be very accurate but I don't have anything to compare it against. It also has another nice feature, a bleeding valve. If your tire is over inflated, keep the gauge's hose attached to the tire a push the bleeding button to lower the pressure in a very controlled manner. Although the gauge is marked in 1 lb increments, I can see differences of about one tenth pound. Has anyone else come across this unit?
  • I just got my first van (Toyota) and am not quite used to dirving one yet. Today while turning in a corner, my right rear wheel rubbed/swiped the curb (gutter).
    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?
  • If you like "analog" stick gauges, take a look at the made-in-America gauges at your local NAPA store. They are excellent, accurate, and sell for $4-$5. You can't beat them.
  • dudleyrdudleyr Posts: 3,469
    Is the radio shack digital gauge the same as the accutire? They look almost identical.
  • cyranno99cyranno99 Posts: 419
    I bought a pencil type gauge years ago. It was a Camel and came highly rated by CR. I tested against my new digital gauge and they both got the same results. I am happy to say that I did not have to wear special gears while testing... thank you for you time!

    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.
  • Batteries wear out whether used or not. At the end of their lives, they have a downward curve of voltage loss that will adversely affect accuracy. Electric instruments are delicate compared to pneumatic instruments.
    I'll stick with the metal cased old style gauges.
  • What do you expect for a tool that only cost $1, $4, or even $12. An accurate air pressure guage is gonna cost $50-$75. On a daily driven street car or pick-up 2 or 3 pounds isn't going to make any noticable difference in performance. The important thing is that all 4 tires are the same pressure. Buy a cheap $4 stick guage and forget about batteries. If all 4 tires are 2 pounds too high or 1 1/2 pounds too low, the average person will never be able to tell the difference. As long as all 4 tires are the same that's all that's important. I have learned through experence at the race track never barrow your friends guage. I only set up my race car with my guage not to say it is accurate, but a guage that is 1 pound off will always be 1 pound off.
  • I've seen tire gauges that can be off by as much as 3psi. Imagine someone driving with 26psi. Boy! That sure helps the fuel economy of the car, not to mention tire wear.

    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....
  • muckyduckmuckyduck Posts: 219
    I bought one of these. I have problems getting it to fit properly on the stem many times. My old tire gauge, the kind that has the rod that pops out showing the pressure, will almost always fit right. Most of the time with the Accutire, it will work the way when you want to reset it - that is, don't fit it on tight, just enough to get some air to set the reading to zero - that is not what I want most of the time - I want it to fit squarely on the stem so I can check the pressure. Is there some trick with this gauge?
  • lee1nyclee1nyc Posts: 60
    I bought the Accutire MS4000 at Sears this week on sale for $16.99. Regular retail is $32.99. They have the less expensive model(s) on sale for $9.99.

    The 4000 works very well for me. It has a digital readout that shows 1/2 lb increments.
  • bodydoublebodydouble Posts: 801
    My wife gave one to me last Christmas. I didn't realize it is such a gem. One question though, how does the lifetime warranty on the battery work? You can't take the gauge apart to replace the battery. So does that mean Accutire will give you a new gauge should the battery run out in your lifetime?
  • lee1nyclee1nyc Posts: 60
    that's the way I understand it.

    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.
  • bodydoublebodydouble Posts: 801
    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?
  • dudleyrdudleyr Posts: 3,469
    If the warranty is 5 years then lifetime is 5 years! Send them the gauge after 5-years for a new battery and they will say sorry it is out of warranty.

    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.
  • bodydoublebodydouble Posts: 801
    bummer!
  • Lithium batteries have very long shelf lives. If you only occasionally use your Accutire gauge, I would bet you could get twenties years out of it.
  • dekindydekindy Posts: 1
    All these guages got outstanding marks from consumer reports in May 2002. #6 was average for ruggedness and #'s 7 & 8 were below average for ruggedness. All were very accurate.
    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
  • akasrpakasrp Posts: 170
    Accutire Model MS-4421BT 'Clearance' Priced $10.48 at Target. Nice blue backlight.
  • last week at PepBoys for 8.99. They had couple of those digital ones there. I didn't know which one to get, so I got the cheapest one. I'm glad I got this one as I like the shape with the finger indent, it's pretty ergonomic IMHO.
  • an air compressor and a new tire gauge. I'll have to see if Sears is having a sale now or else go to NAPA and see what they have.

    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.....
  • dplavdplav Posts: 6
    I bought the Accutire MS-4020B and had trouble getting it to fit to get a proper readout, anyone try the newest Accutire MS-4100B. Costs about $30, should be worth it, but wanted to see if anyone used it and their experience.
  • nextmoonnextmoon Posts: 386
    I bought one last year and also had trouble getting the nozzle to fit over the valve stems on two cars. The nozzle looks too small to fit and seems to be made of plastic. Not sure of the exact model number.
  • 5539655396 Posts: 529
    "The important thing is that all 4 tires are the same pressure. Buy a cheap $4 stick guage and forget about batteries. If all 4 tires are 2 pounds too high or 1 1/2 pounds too low, the average person will never be able to tell the difference. As long as all 4 tires are the same that's all that's important."

    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.
  • 5539655396 Posts: 529
    #38 of 48 How do they define lifetime? by bodydouble Jun 10, 2002 (8:14 pm)
    "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.
  • Please help me find the following, any recommendations that meet this spec would be appreciated.

    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
  • QuickCar Deluxe Digital Tire Pressure Gauge


    Meets all your requirements, except that it's 0-50psi, not 0-90psi.
  • bottgersbottgers Posts: 2,030
    .....and the guy who replaced them said he put 30 psi in them. When I got home I checked them with my guage and all 4 tires read 34-35 psi. I don't know if the tire guy's gauge was off or if my cheap gauge with the little square rod that protrudes out from the middle was off. At any rate, I think I definitely need to look into one of these Accutire gauges. It's amazing how many vehicles I see on the road with underinflated (or just improperly inflated) tires and how many people don't realize (or care) how important proper tire pressure is.
  • bottgersbottgers Posts: 2,030
    If you're looking to purchase an Accutire gauge from the internet, make sure you'll actually be getting an Accutire gauge before you order. For example, doing a search on bizrate.com for Accutire shows that Circuit City sells them. I actually went to our local CC after their web site indicated they had the Accutire gauges in stock. The gauges they had were in fact made by Nextech and they didn't have a single gauge with the Accutire name on it. The Nextech gauge I looked at looks just like one of the Accutire gauges and its part number (63-1113) is listed on CC's site as an Accutire gauge. I will be contacting the Tire Rack to find out if the gauges they sell are actually made by Accutire. If so, I'll probably just order one from them.
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