How accurate is your tire Gage???

[Ron]

We are familiar with the importance of keeping our tires properly inflated and I am sure most of us check them often.  However, how accurate is your tire gage and how do you know?  Some time back I bought a new tire gage at a truck stop the dial type.  When I compared the readings with my old gage there was almost 10 pounds difference in the readings on the motorhome tires while when measuring the toad tires they read pretty close.  Since I found out other pressure gages never seemed to read exactly as mine do.  Then I had a chance to compare reading with a cage that was suppose to have been calibrated and found the newest gage read 5 lbs high and the older gage read nearly 5 lbs low.

Do you know how accurate your tire gage is, and if so how did you determine this?

Where would one go to have a tire gage checked for accuracy.

Where can an accurate tire gage be purchased and what brands are recommended?

 

[Just Lou]

Ron, GREAT question(s)

I've been asking myself those same Q's.  Boy do I need the answer.
New tires, long trip, old gauge. etc... 

 

[Kirk]

I recently read a piece about that issue, I think it was in Motorhome Magazine. In any case, they claimed that the new digital gauges are more accurate and stay that way longer. As one from the electronic field, that clearly could be true, but quality of product is vital.

 

[Gary RV_Wizard]

I have several gauges, digital, dial and slide types, and get readings all over the map.  The Pressure Pro system gives yet another set of readings.  Have no idea which, if any, is actually correct. A lot depends on the contact the gauge makes with the valve and I have one gauge that works very poorly with the valves on the coach but OK on the car tires.

My Sears digital gauge gives the most consistent readings and is convenient, so I use it the most. It reads within about 2 lbs of the high quality, trucker style, dual foot sliding gauge I got from the National Tire Manufacturers Institute and both of those are close to the Pressure Pro readings, so I feel fairly comfortable that they are "close enough".

Since tire pressures vary a lot by temperature, ambient pressure, road surface and a host of other factors, they probably don't have to be all that accurate anyway. But readings off by 10 lbs are a bit scary and I have at least one gauge approaching that, compared to one of more of the others.  Since it is lower than all the others, I don't use that one anymore. Probably ought to throw it away.

 

[John From Detroit]

Several years ago there was an article in one of the automotive magazines on just this topic, how accurate are the guages.  And alas, their conclusion was not really that good.

However technology changes,  The result today may be different.  (I truly do not know)

The best way to get an idea is to use several guages, if you have to borrow a few.  If you use, say 10 guages one after the other and they are all within a pound or two (note, the tire pressure will go down as you run multiple tests) I'd say those guages are accurate... If say, 9 of them show oh, say, 95 lbs, and the 10th shows 120 or 85.. I'd not buy that brand.  Short of setting up a test jig where you know the exact pressure that's about the only way to test time.

Finally.. User introduced error is possible as well.. You have to properly apply the guage, if you missapply it will read low as a general rule

 

[Karsty]

As I continue to weed my way through 1000's of topics and posts in this site I seem to find more and more older topics that are relevant to my current situation.

HOW ACCURATE IS YOUR TIRE GAUGE??

I have never been so more aware of (or maybe that should be paranoid of) the importance checking and monitoring tire pressure since I purchased my ERA.

I currently have and have been using a double headed sliding truck tire gauge. It seemed to suit my needs until now. I just installed the DORAN 360RV TPMS and am very pleased with the results but they are different than the reading I am getting with the tire gauge.

It does lead to one other question ... which may have been answered elsewhere ... I will keep looking ...

"How much of a difference in tire pressure between tires is acceptable??" I don't want to be running out every morning to add 1 or 2 pounds to one tire because if reads higher or lower than the other one ... unless it was absolutely necessary?? For example the left front currently reads 59 PSI, while the right reads 61 PSI. According to the gauge they are both at 60 PSI or enough that my eyes can distinguish any difference. I have the TPMS set to 60 PSI.

Any thoughts would be appreciated. I'm figuring that since the last posts in this thread was from 2006 that the digital gauges have improved since the last ones that I owned and were junk ... IMO (constantly not working ... maybe due to cold winter weather) ... maybe it is time to try another one.

 

[Clay L]

At a Winnebago Grand National Rally a few years ago Michelin had a setup in their booth to measure tire gauges.
I took my digital Accu-trac (Camping World) and my mechanical plunger type (a truckers supply store in NH - sort of like a Toys R Us store for truckers) to them for an accuracy check.
The digital one was off by 1 1/2 psi and the mechanical one was dead on.

Of course the mechanical one can't be read with the same precision as the digital.

As I recall they measured at 100 psi  which is close to the psi most us will be checking.

 

[Gary RV_Wizard]

You can expect up to 3% variation between any two reasonable quality gauges. Probably more like 2% if measuring closer to the mid-range of the gauge than the end of its range. That means on a 100 psi tire, two gauges could disagree by as much as 6 psi, i.e. one is +3% and the other -3%, but more typically they will be within 2% of each other.

The real question is whether your gauge reads consistently, i.e. can you repeat the measurement 3-5 times and get the same reading each time. If  you can, you can be comfortable in setting your pressures with that gauge, and comparing it to other tires measured with the same gauge. Don't worry if your TPMS is 2 psi off from your hand gauge, as long as it remains consistent.

You should be setting your tire pressures at least a couple psi above the minimum required for the load, to allow for minor variations in load, conditions (and on mechanical gauges, your eyesight!) . Personally, mine are set 5 psi higher than the minimum needed.

 

[cva61]

When I ran shops for trucking companies I purchases all of my guages from Myers Tire Supply.  They have "MASTER GUAGES" and "GUAGE CALABRAITION GUAGES".

Here is the URL for their guages. http://www.myerstiresupply.com/shop/shopdisplayproducts.asp?page=1&id=68

 

[JerArdra]

June 2012

Last month or the month before Consumer Reports had a test report on a dozen tire gauges.  The most accurate and best one was the ACCUTIRE model MS-4021B.  It measures from 5 lbs to 150 lbs and costs $10.  Google it.  Yes I bought one.

JerryF

 

[John From Detroit]

When I had my rig weighted by Aweigh We Go (www.rvsafety.com) they compare tire guages against their lab calibrated guages.

The told me the Pressure Pro sensors they have tested were always withing +/- 1 PSI.

On my tires that is <1 percent and not at all worth thinking about.

 

[Foto-n-T]

For example the left front currently reads 59 PSI, while the right reads 61 PSI. According to the gauge they are both at 60 PSI or enough that my eyes can distinguish any difference. I have the TPMS set to 60 PSI.

I'd say that for a side to side differential that's pretty good.  Keep in mind that you don't have to be driving for the pressure to change in your tires.  A tire on the side that is facing the sun will have a slightly higher pressure than one in the shade simply because of the temperature difference.  I'm just anal enough that when I'm matching tire pressures I try to do it "before" the sun bakes the tires or better yet I do it in my storage unit.

Some Thoughts On TPM Sensor Accuracy
I'll deal strictly with Doran Mfg. here as that's the system which I use.  Doran Mfg. originally targeted the trucking industry as it's primary market, RV's and autos were secondary at best.  As such Doran Mfg. has a huge liability exposure, we know how the attorneys love to blame professional drivers for the inability of thier clients to pilot cars.  That liability exposure (in my mind) means that Doran Mfg. had better be extremely sure that their sensors are accurate, if not they could cause an accident which could result in millions of dollars in awards.  I'm going to make the assumption that pretty much ALL TPMS manufacturers are under the same scrutiny when it comes to liability as well.  Having said this:  I would trust my TPMS over just about any chinese tire gauge.  By the way, if anybody finds a tire gauge made in the USA I'd like to know.

My sensors read approximately 2psi below my digital.  I set the TPMS at 65psi for the 5th wheel and use my digital to run them up to 67psi and all is well.  I'm less picky about the truck though as I keep the H rated tires on it at around 100psi for the drives and 95psi for the steers.