Tire pressure monitor recommendation?

[mstephens]

Just a follow up.
After 2500 miles with my TPMS (a DILL), it's one of the most useful additions I have made to my rig. It is fantastic to be able to check all my pressures while hitching up, and then monitor them on the fly. I've been in every kind of temp and elevation and road, and it's great to not be worried about a tire you can't see or feel. For all who can afford to add this, you will find it a good investment I think.

Tires is kind of the "biggie" while towing, and the more you know about what they are doing, the more confident you can feel. Now, if only there was a similar device to read out the lug nut torque....

[73shark]

Originally Posted by dznf0g

Ah, that's true, didn't think of that shortcut.

What did the vendor say?

They both said that it measure the air temp. at the valve stem. From that statement I concluded that it's an actual temp. measurement, not a calculated value from pressure change.

One was Tire Traker and the other was TST from Great RV Products.

I'm pretty sure that to put them on the rear, I'd have to remove the outer dual. Then to add air I would have to do it again. While the TSTs have a flow-thru version so you can add air w/o removing, I think the size would preclude installing on the duals. It's enuf of a PITA to add air now.

I think I've talked myself out of the external mounted TPMS. Maybe when I need to replace the tires, I'll look into some internal mounted ones.

[dznf0g]

Originally Posted by 73shark

They both said that it measure the air temp. at the valve stem. From that statement I concluded that it's an actual temp. measurement, not a calculated value from pressure change.

One was Tire Traker and the other was TST from Great RV Products.

I'm pretty sure that to put them on the rear, I'd have to remove the outer dual. Then to add air I would have to do it again. While the TSTs have a flow-thru version so you can add air w/o removing, I think the size would preclude installing on the duals. It's enuf of a PITA to add air now.

I think I've talked myself out of the external mounted TPMS. Maybe when I need to replace the tires, I'll look into some internal mounted ones.

Wow! that can't be even close to the temp of the carcass. What kind of readings do you see in relation to ambient temps...ie, how much higher?

[Wingeezer]

Originally Posted by dznf0g

Wow! that can't be even close to the temp of the carcass. What kind of readings do you see in relation to ambient temps...ie, how much higher?

Probably true, but isn't it more a matter of one tire temperature versus its mates rather than an absolute reading?

I just had an internet chat with a fellow on the Hawkshead website and he too said that they do measure temperature - but then, no guarantee he really knows I suppose!

I tend to feel that despite the valid points that you make, it would not be unreasonable to think that a bearing that was really going bad, or a sticking brake, would conduct sufficient heat from the hub or drum, through the wheel to the metal valve stem to register a significantly higher temp at the sensor compared to the wheels with normally performing bearings & brakes.

Just my own assessment of course and could be wishful thinking!


Brian.

[Wingeezer]

Originally Posted by mstephens

Just a follow up.
After 2500 miles with my TPMS (a DILL), it's one of the most useful additions I have made to my rig. It is fantastic to be able to check all my pressures while hitching up, and then monitor them on the fly. I've been in every kind of temp and elevation and road, and it's great to not be worried about a tire you can't see or feel. For all who can afford to add this, you will find it a good investment I think.

Tires is kind of the "biggie" while towing, and the more you know about what they are doing, the more confident you can feel. Now, if only there was a similar device to read out the lug nut torque....

Agree very much with what you say, but of course owning a TPMS should not replace a walkaround to check you tires at every stop - no doubt you do this also, but I just wanted to emphasize that - in my view at least - the TMPS should not be looked upon as an alternative to frequent visual inspections

A few years back, with a non-AS trailer, I had a set of marathons start flying apart half way across Texas. I felt unusual vibrations in the tow vehicle, stopped for a looksee, and found one tire with a chunk of tread at least a foot long by the full width of the tire completely gone (found it stuck up in the wheel well!). Closer examination revealed two other tires starting to delaminate.

Luckily a little outdoor repair facility behind a fast food restaurant in Fort Stockton had four trailer tires - gosh knows what make they were, I was just happy to get them. I remember having to pay him overtime though as it was close to 6pm on Friday! saved me having to stay in Fort Stockton until Monday morning!

At that time I had no TPMS, but none of the tires had lost any air anyway despite their missing tread, so I doubt it would have been much help.

I was very lucky that damage to the trailer was minimal, but this incident reminds me to to a walkaround at every pee or fuel stop!


Brian.

[Ag&Au]

Originally Posted by Wingeezer

Probably true, but isn't it more a matter of one tire temperature versus its mates rather than an absolute reading?

I just had an internet chat with a fellow on the Hawkshead website and he too said that they do measure temperature - but then, no guarantee he really knows I suppose!

I tend to feel that despite the valid points that you make, it would not be unreasonable to think that a bearing that was really going bad, or a sticking brake, would conduct sufficient heat from the hub or drum, through the wheel to the metal valve stem to register a significantly higher temp at the sensor compared to the wheels with normally performing bearings & brakes.

Just my own assessment of course and could be wishful thinking!


Brian.

We all have different expectations from our TPMS. However I generally agree with Brian.

Hawkshead racing seem to be pretty much a Mom and Pop company. I'd say the odds are good that you are talking to the owner. That is one reason I like dealing with them.

Basically our TPMS sits there and minds its own business and we mind ours. If my wife is driving, I will probably scroll through the readings and make sure everything looks OK. I imagine it annoys the TPMS to have me looking over its shoulder. But for the most part, I wait for it to do its job and tell me if something is amiss. For what is is worth, on our last trip, I aimed my IR thermometer at a couple tire sidewalls at a rest area and found them to be within 1 deg F of the TPMS. That doesn't prove a thing, but I found it interesting.

Ken

[purman]

Originally Posted by w7ts

. For what is is worth, on our last trip, I aimed my IR thermometer at a couple tire sidewalls at a rest area and found them to be within 1 deg F of the TPMS. That doesn't prove a thing, but I found it interesting.

Ken

Close enough for me. And also tells me that its not an estimate of temp based on psi gain.

I don't need to know the exact temp. Just need to know if I can fry an egg for lunch on the tire

[dznf0g]

Originally Posted by purman

Close enough for me. And also tells me that its not an estimate of temp based on psi gain.

I don't need to know the exact temp. Just need to know if I can fry an egg for lunch on the tire

Guys, I'm not trying to be arnry, nor am I trying to say that TPMS temps are no good. I am saying that I have found noplace where I can find a correlation between the reading and what actual temps are where it matters, at the shoulders and across the tread ON THE INSIDE, where the bonding of tire components are.

Measuring the sidewall (where???) may very well match the air temp in the valve stem, but how do those temps correlate to the temp at the shoulder...and what is your baseline for accepting your readings elsewhere as normal? And what IS normal at the shoulder? The only readings I can find concern NASCAR and on Hoosier tire site refering to racing tires and conditions. Not a good comparison.

See the graphic below: The temps of the middle of the sidewall don't change much, but they claim that 14* can make a difference at the shoulder??????? These are questions.....I don't have the answer, but we need a baseline for normal, regardless of how or where we measure.

[jhart657]

I purchased a TST system about a year an a half ago. The system measures both pressure and temperature. Earlier this year, on the way out to Utah, the audible alarm on the system alerted me to a high temperature condition on the Airstream's left rear wheel. Turns out that the brake had locked up and was frying the wheel. I was able to safely pull off the highway and get to a repair facility. I highly recommend this TST system.
Juergen

[purman]

Originally Posted by dznf0g

Guys, I'm not trying to be arnry, nor am I trying to say that TPMS temps are no good. I am saying that I have found noplace where I can find a correlation between the reading and what actual temps are where it matters, at the shoulders and across the tread ON THE INSIDE, where the bonding of tire components are.

Measuring the sidewall (where???) may very well match the air temp in the valve stem, but how do those temps correlate to the temp at the shoulder...and what is your baseline for accepting your readings elsewhere as normal? And what IS normal at the shoulder? The only readings I can find concern NASCAR and on Hoosier tire site refering to racing tires and conditions. Not a good comparison.

See the graphic below: The temps of the middle of the sidewall don't change much, but they claim that 14* can make a difference at the shoulder??????? These are questions.....I don't have the answer, but we need a baseline for normal, regardless of how or where we measure.

I don't think any TPMS dies this. You would have to have a temp strip on the inside on the tread to get the true temp. What we are getting is the air temp inside the tire. Which may be a couple degrees cooler. Who knows. But it give a baseline to see if your tires are running really hot. I ran 114 f this summer in 106 f outside temp. I'm betting the road was at least 110 or more. That blacktop gets hot.

[dznf0g]

Originally Posted by purman

I don't think any TPMS dies this. You would have to have a temp strip on the inside on the tread to get the true temp. What we are getting is the air temp inside the tire. Which may be a couple degrees cooler. Who knows. But it give a baseline to see if your tires are running really hot. I ran 114 f this summer in 106 f outside temp. I'm betting the road was at least 110 or more. That blacktop gets hot.

uggggg......that's not what I am saying! I am saying:

1) What is the baseline temp for tire damage (sudden and/or repeated cycling) where damage occurs at the shoulder and tread? Dunno.

2) What would your reading (lower) be at the stem (TPMS) when the shoulder is at a damaging (sudden and/or repeated cycling) when the temp at the shoulder is too high? Dunno.

Juergen, Do you recall what the temp was on your TPMS when the alarm went off? I did read on one of the TPMS sites that their alarm (stem sensor) goes off at 160*. IS that a good correlation to extreme shoulder temp? Dunno, I can't find any data?

[jhenry235]

In June 2012 I purchased and installed a tire pressure monitoring system on all 7 wheels of my 34' Airstream. HCI Corporation Cerritos, Ca. 562-926-7123..It saved my butt...On my first trip with this system installed I crossed over a Rail Road Crossing at 55 mph...It was a violent crossing...Within one minute I started to get an audible warning of low pressure...It showed the middle tire pressure going down...I had to slow down and go about 6 miles before I found a place to pull over...AAA came out and changed the tire...I found a Les Schwab tire store...They checked all 6 tires...All 6 tires were trashed....They had been in excellent shape with about 9000 miles on them...I can't imagine what kind of disaster would have occurred had I made it to the interstate not knowing I had a flat tire....I sent CalTrans a letter putting them on the hot seat by saying this crossing is a dangerous road condition. I would highly recommend a tire pressure monitoring system...

[jhart657]

The TST system allows you to program both pressure and temp alarm points. I believe that the pre-set temp alarm point is 157 degrees. The system scrolls through both temps and pressure on a continual basis. Great peace of mind.
Juergen

[GCinSC2]

I have had the Dill 1504 for about 2 years now. IMHO a TPMS is a serious consideration for saftey, can't prevent a loss of PSI but certainly can warn and give you a chance to prevent major damage.

The Dill uses internal monitors, requires a tire shop and they must know what they are doing, but today I bet most are trained due to pass car useage.

I give my display a could be slightly better rating in terms of overall packaging and mounting, but I don't have much of an issue with the data provided. PSI presented on a continous cycling tire to tire display. Temp is a seperate function, push button and it cycles thru temps.

On earlier shakedown trips I tried to get some data, but it's not presentable, can't pinpoint conditions etc.

From the Dill owners manual about temp, Over 176 degrees:
Display shows temp and digits flash.
Audible warning.
Abnormal icon goes red.
Tire indicator will become red.

For PSI you can set the system to your PSI, follow owners manual.

Per manual system will alarm at 20% lower than setpoint and at 30% higher than setpoint.

Each wheel has a unique transmitter and the display has a matched receiver in each port. To rotate the tires for service, you relocate the receiver key to the new position.

System comes with a pigtail antenna and a remote mag base roof mount, I needed the mag base antenna.

Doing something proactive sure beats doing nothing.

Slighty unrelated, no issues on my MAXXIS tires to report.

[slowmover]

The tire damage/internal heat question came up several years ago on another [related] thread. Around 170-180F, IIRC. And the number used by TPMS systems for alarm. Past my wanting an interior-mount sensor, it would seem that unit longevity & customer service are the highest priorities for an aftermarket system.

[dznf0g]

Originally Posted by REDNAX

The tire damage/internal heat question came up several years ago on another [related] thread. Around 170-180F, IIRC. And the number used by TPMS systems for alarm. Past my wanting an interior-mount sensor, it would seem that unit longevity & customer service are the highest priorities for an aftermarket system.

I would like to know more about that 170 - 180*. What source did it come from? Is the 170 - 180* a damaging temp at the point of highest heat (shoulder area) and how does that correlate to a reading by TPMS inside at the stem and outside at the stem and with an infrared on the outside of the shoulder and tread?

That's the stuff I can't seem to find anywhere on the web. The racing sights seem to use the 210 - 220* range as a bond failing point, but I don't think that can translate to a street tire.

[slowmover]

There wasn't (and isn't, IIRC) a set temp for beginning tire problems due to some conflicting factors, but the alarm set temp by TPMS systems comes close enough.

Tireman9 has some info on his web blog.

.

[dznf0g]

Thanks, Rednax,

Roger has a SIGNIFICANTLY different formula than I had read before and different than Capriracer.....By Roger's formula, I am fine at 65psi and seeing a 7 - 9 PSI rise as that would only be a 35 - 45* rise in temperature over ambient. That actually correlates with my observations on my last trip. I read 105 - 109* across the treads of all four tires by the IR thermometer on a 70* day. OHHHHH, who to believe?

RV Tire Safety

[slowmover]

I don't really think there is that much difference so much as an approach to problem solving. One can have this effect via specific versus general approaches . . and both be correct. Even if one seems to say something different. Using one way to get to something specific may seem incorrect, IOW. And vice-versa.

[dznf0g]

Roger's methodology allows for about DOUBLE the psi rise relative to temp as the others. That's significant.