4 different tire gauges, 3 different readings

[fun time]

I purchased a new non-digital tire gauge about a year ago. Been using it without any problems. Saw another one at the local auto parts store and thought I'd buy it. Came home and just for the heck of it I thought I would compare the two, one digital the other dial type. Wow.......6 pds. difference in readings on the same tire within 1 minute readings? I thought this cannot be possible. Borrowed my neighbors and got another third different reading? It registered three pounds different than the first and second ones. What the heck gives here. Got out my very expensive one from the MH which I paid $79.00 for several years ago and the took another reading. It came within 2 psi of the first one? So, are number 1 and 4 the acurate ones? Which one do I believe and why four different psi readings with 4 gauges? This is perplexing. Any experts here?

[Mike Canter]

Those "stick gauges" are really inaccurate. The digital gauges tend to be more accurate. I have three digital gauses and they all read within a pound of each other so I assume they are correct. I drag racing where we use 5-6 lbs in the drag slicks we have to pay about $200 to get a gauge that is accurate and we get them checked and calibrated all the time because we adjust tire pressures by a quarter of a pound. For a MH that requires around a 100 lbs in a tire being 5 lbs off is not the eand of the world and it is best to always run about 5 lbs above what is called for.

[hamguy]

Quote:

Originally Posted by fun time I purchased a new non-digital tire gauge about a year ago. Been using it without any problems. Saw another one at the local auto parts store and thought I'd buy it. Came home and just for the heck of it I thought I would compare the two, one digital the other dial type. Wow.......6 pds. difference in readings on the same tire within 1 minute readings? I thought this cannot be possible. Borrowed my neighbors and got another third different reading? It registered three pounds different than the first and second ones. What the heck gives here. Got out my very expensive one from the MH which I paid $79.00 for several years ago and the took another reading. It came within 2 psi of the first one? So, are number 1 and 4 the acurate ones? Which one do I believe and why four different psi readings with 4 gauges? This is perplexing. Any experts here?

I was the manager of a Standards Lab for a major electronics company. For commercial equipment, +/- 10% of reading or even full scale is not unusual. Take the one reading in the middle of the 3. Should work.

[Hikerdogs]

Motorhome Magazine did a review of tire gauges last summer. They found the Milton model S976 to be the most accurate of all those tested including high end digitals. I have several of them left over from my days as a mechanic and still use them regularly.
Most tire companies have a master gauge that's checked and calibrated (if necessary) every few months. They will gladly check your gauge against theirs and let you know whether yours reads high or low and by how much. I took my 20+ year old gauges to Pomps Tires here in town and found they were still within 1 lb of the master.

The nice thing about the Milton S976 is that they are relatively inexpensive (around $20.00, are well built and can take a beating. If they ever do go bad they can be rebuilt for only a few dollars.

[edj]

Quote:

Originally Posted by Hikerdogs The nice thing about the Milton S976 is that they are relatively inexpensive (around $20.00, are well built and can take a beating. If they ever do go bad they can be rebuilt for only a few dollars.

Here is one place to get the Milton air guage.

[Mike Canter]

In the Family Motor Coaching Magazine they tested all kinds of gauges and found the Accutire Digital gauges to be most accurate and repeatable. That is what I have used for years. The problem with stick gauges like the Milton is they are not accurate in cold weather because the slide part sticks and they are not accurate if the slide part gets dirty. I do have one that I have had for years and keep it around for emergencies or if somebody wants to borrow a gauge.

Amazon.com: Accutire MS-5520B RV & Truck Gauge large LCD w/.5 resolution 0 - 150 PSI: Automotive