Tire Pressure

Several years ago Consumer Reports did a study on tire gauges. At the time digital ones were just coming on the scene. They gathered up hundreds of different gauges and several samples of each. What they found, was, that the simple stick type gauge was extremely accurate, no matter how cheap or who made it, and that digital ones of that time were for the most part, also just as accurate, but not worth the extra money.

A couple of gauges were eliminated due to defects in the design of the head, but all in all, they all tested accurate within I think it was a pound, and it came down to the design and angle of the "foot", straight, angled, double. and whether it had a depressor to release pressure.

I have removed the wheel simulators from my Sprinter, and I have found that a tire gauge with a long stem and a foot that has a straight end and a angled back fitting work perfectly. I also got a long Milton service end to use that is designed the same way.

https://www.amazon.com/gp/product/B004QI1WEA/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1



This is an interesting one, very similar to mine.

https://www.amazon.com/TireMinder-Precision-Replaceable-Batteries-Warranty/dp/B01301305W/ref=sr_1_75?s=automotive&ie=UTF8&qid=1469026675&sr=1-75&keywords=digital+tire+gauge

Same/similar but cheaper

https://www.amazon.com/TireMinder-TMG-DUAL-2-Digital-Pressure-Attachments/dp/B00C5THRBO/ref=sr_1_101?s=automotive&ie=UTF8&qid=1469026756&sr=1-101&keywords=digital+tire+gauge

This is the gauge I have. Paid about $10 at Ollies for it, Slime has discontinued it. It does work well.

https://www.amazon.com/Slime-20165-Digital-Truck-Gauge/dp/B007OXC97S/ref=sr_1_141?s=automotive&ie=UTF8&qid=1469026837&sr=1-141&keywords=digital+tire+gauge



Charles

ron.dittmer wrote:
What I practice using various gauges. I use a stick gauge. I love dial gauges but don't have one that reads more than 60 PSI. My experience with a digital gauge did not go well. I should look into buying one specific for dualies.

My Process..........
1) Check tire pressure before the driving day starts, BEFORE the sun hits any one tire.
2) All 4 rear tires are as close to the same pressure as can be possible using my stick gauge.
3) The same for the front tires, but the pressure is not the same as the rear.

Regarding pressure settings......
I have experimented over the years. I have followed the proper PSI per the actual load on the tires and they all visually appear significantly under-inflated. I verified the reading with my trusted gauge by comparing the reading against other gauges. So I add 5 additional PSI for peace of mind so the tires don't look so under-inflated. When I add 10 PSI more, they appear just about right but then the ride gets too harsh and the rig handles worse.

According to the documentation from my Michelin "E" rated tires and my RV manufacture, I should have 60 PSI in the 4 rear tires and 65 PSI in both front tires. My practice is 5 more PSI to those numbers. My rig is less than 24 feet long. It is built on a 2007 E350.

I have long stainless braided extensions that were installed 9 years ago and never disturbed. (Yes the tires are 9 years old now) I think it's time to remove the extenders for the sake of reliability. I fear an unnoticed leak will produce a blow-out.

Can anyone recommend a good DIGITAL tire gauge that works well for dualies without valve extensions? I don't mind crawling on my back to get a reading.

TPMS is best way of knowing if you are loosing air from tire, valve or hose extenders.

Based on checks against ISO standard laboratory gauges I have found that the $12 Accutire is accurate to +/- 0.5 psi
I use the 150 psi max (good to measure 30 - 130 psi) Accutire as my "Master" and only use it once a month to check the reading of my "work" gauge. Since I run hose extenders


I don't need a dual foot gauge.

Sam Spade wrote:

PSW wrote:
By the way, I also carry my infrared temperature gauge with me and I check not only the tires when they are cold and hot, but I also check the temperature of the tires when we stop for gas.

Let's play a little what if:
What if.....you check the temps and one of the inside rear duals is 30 degrees hotter and the pressure is up maybe 5 psi. What will you do about that if there is no obvious sign of a physical problem with the tire ?? Substitute whatever numbers you want, for any one....or two....of the tires.

Higher temps can mean that there is a brake dragging or a bearing going bad but what if you check the rotor temps and the hub temps and they are not much different; then what ??

MANY years ago they stopped putting calibrated gauges on cars and most trucks.....and then went to "idiot lights" because too many "idiots" were seeing a slight change in the gauge and running right to the shop and insisting that something was wrong.....when there usually wasn't.

Sometimes you can be TOO careful.

False premise with the question.
You should only check or set your tire pressure when the tires are "cold". This doesn't mean in the refrigerator but not warmed up by either being the sun in previous 2 hours or driven more than one mile in previous 2 hours.

IR guns are OK for conductive material such as metals but rubber is an insulator so you are not reading the hot part of the tire. Temperatures can vary by 100F within 1/4".

Pressure does not have that problem. Confirm your digital gauge is reasonable accurate (+/- 3 psi or less) from gauges used at your tire dealer.

When cold all tires on an axle should have the same inflation when checked.
Tire inflation changes by about 2% for 10F
Inner duals might normally run a few degrees hotter because of less cooling air flow across the tire sidewall and/or wheel.

Hank85713 wrote:
ron got my digital from camp world. Has straight and goose neck in kit. about $30. I bought 3, 1 for each (truck, rv) gave 1 to son in law.

I have seen them at auto zone and oriellys but not too often.

Come to think of it I also saw at a pilot truck stop. They read up to 150 if I remember right.

Thanks Hank! I will check them out.

Sam Spade wrote:
You don't NEED a scientific instrument to detect a significant difference in temperature; the key word is SIGNIFICANT.

But if it makes you feel good, far be it for me to spoil your party.

You started off by saying that looking for a difference in temps is basically a waste of time; overkill. You even used the example of 30 degrees difference between two adjacent duals, which IS significant (and unlikely to be caused by a bearing or caliper, which would affect BOTH tires). Yet you yourself now admit to doing just that, albeit in a much less accurate way. So in reality, a temp gun is simply an alternate way of doing exactly what you admit you do. Just like a tire pressure gauge is a "scientific instrument" to replace a simple tire thumper.

Even with a temp gun, I too am looking for a SIGNIFICANT difference. But I don't have to get down on my hands & knees and reach under the vehicle to touch the inner duals. For less than $30, it's worth it to me; cheap, faster, easier, and accurate. As opposed to Hands; cheaper ($0), but slower, more difficult, inaccurate (and dirty). But hey, party on! ;)

ron got my digital from camp world. Has straight and goose neck in kit. about $30. I bought 3, 1 for each (truck, rv) gave 1 to son in law.

I have seen them at auto zone and oriellys but not too often.

Come to think of it I also saw at a pilot truck stop. They read up to 150 if I remember right.

What I practice using various gauges. I use a stick gauge. I love dial gauges but don't have one that reads more than 60 PSI. My experience with a digital gauge did not go well. I should look into buying one specific for dualies.

My Process..........
1) Check tire pressure before the driving day starts, BEFORE the sun hits any one tire.
2) All 4 rear tires are as close to the same pressure as can be possible using my stick gauge.
3) The same for the front tires, but the pressure is not the same as the rear.

Regarding pressure settings......
I have experimented over the years. I have followed the proper PSI per the actual load on the tires and they all visually appear significantly under-inflated. I verified the reading with my trusted gauge by comparing the reading against other gauges. So I add 5 additional PSI for peace of mind so the tires don't look so under-inflated. When I add 10 PSI more, they appear just about right but then the ride gets too harsh and the rig handles worse.

According to the documentation from my Michelin "E" rated tires and my RV manufacture, I should have 60 PSI in the 4 rear tires and 65 PSI in both front tires. My practice is 5 more PSI to those numbers. My rig is less than 24 feet long. It is built on a 2007 E350.

I have long stainless braided extensions that were installed 9 years ago and never disturbed. (Yes the tires are 9 years old now) I think it's time to remove the extenders for the sake of reliability. I fear an unnoticed leak will produce a blow-out.

Can anyone recommend a good DIGITAL tire gauge that works well for dualies without valve extensions? I don't mind crawling on my back to get a reading.

The awesome part of being an RV'er is we can do what we want, how we want, the best way we see fit. No need to get upset about anyone else's opinion. If it works for you, keep doing it. If it gives you peace of mind, what's the harm?

4x4van wrote:
then I would suggest that your hand is the opposite; much less accurate and therefore a waste of time. So why bother with the hand?

I know you aren't going to understand this but it's a matter of degrees here (no pun intended).

You don't NEED a scientific instrument to detect a significant difference in temperature; the key word is SIGNIFICANT.

But if it makes you feel good, far be it for me to spoil your party.

Sam Spade wrote:

4x4van wrote:
So what would YOU suggest; continue mindlessly down the highway?

Pretty much, yes.

A bearing can be a little bit tighter than all the rest or a caliper dragging a little bit more......and not ever cause a significant problem.

Of course, a significant change from the normal pattern probably does mean that something is amiss but if it really IS it probably will show up in other ways too.......like the brakes pulling to one side or smelling something hot when you stop at a light.

I am in no way saying what you are doing is wrong, just that it is overkill.

I walk around my rig at every stop. My temperature gauge is the palm of my hand.

So you wait till there is at least two symptoms before looking for the cause? Or is it three? Not sure if I'm following your logic there. As you say, what I am looking for is something out of the normal pattern. And if I find THAT, I am going to look for the cause, even BEFORE it manifests itself into other symptoms...that "next" symptom could be a blowout at speed...sorry, not gonna go there.

The temp gun is no different than your palm, just easier, more accurate, and keeps my hands clean. So if the temp gun is overkill, then I would suggest that your hand is the opposite; much less accurate and therefore a waste of time. So why bother with the hand?