Tire pressure monitoring systems

A couple years ago, driving home through Iowa, my TST started beeping.
Drivers side rear inner showed 75 psi, down from 95.
I pulled off the highway immediately. Before I could get out the cellphone to call coachnet it had gone to Zero. Coachnet got there within the hour, installed my unmounted spare, and I was on my way.

I had several tire problems with my first motorhome, an F53 pace arrow. A curb hit. A blowout. A wake up in the morning to find no air in a tire.

I fought the TPMS concept hard. It still bothers me that these things defeat the tire valve and rely on an o ring to seal all the air into the tire. I checked the pressures in that Pace Arrow every morning and then every stop. And said that was enough. And it was not enough.

When I bought the DP, I also got a 10 tire TST system, and when I got the rear tires replaced, kept the best as an onboard unmounted spare.

I had issues with the TST at install, they sent me 2 sensors free immediately. The issues turned out to be operator error programming the system. Last year my display went funky. I pulled the system off to test it, and now I cannot find it! one more look thru the RV tomorrow, and I'll be buying another system. At least I still have the 4 toad sensors...lol.
If only they made one that could read the factory sensors in the new jeep?

I am really leaning toward the TST system but I am not real crazy about the display. Seems they use the same system for all vehicles. Having only need to monitor 6 tires, the "extra" trailer on the screen is frankly a waste. I guess it would apply if I added a toad. I also don't like the fact it's sideways. Call me OCD but it seems like the display should align with the RV (IE forward) I like the fact that they are pass through sensors with replaceable batteries. The Tiretech is also on my list. It's considerably cheaper than the TST and I like the display much better. But it does not have pass through caps. Can I assume these systems are OK with valvle extensions? Don't care for the pressure pro monitor at all. I am sure it's a good system. Frankly I just want the best bang for my buck. I know most of you like to chime in about what's x dollars compared to a tire failure, etc etc? But more money does not always mean a better system. Surprisingly there is little in the way of reviews etc for any of these systems.

lanerd wrote:

Effy wrote:
How exactly do the external screw on sensors measure accurate tire temperature? Seems spinning on a cap outside the tire in the ambient air couldn't provide an accurate tire temperature could it?

You are missing the whole point of having a TPMS. You measure accurate tire pressure with an external gauge prior to the tires heating up. The TPMS is just to alert you of a tire malfunction caused by low/high pressure or temperature. Knowing accurate tire pressure going down the road is redundant as it changes with speed, altitude, temperature, road conditions....ect.

Ron

I am not missing the point, I am just asking a question. I get how they work and why, I was simply questioning that if a unit measures temperature, how does it do that accurately while being on the valve stem, spinning in the ambient air?

Effy wrote:
How exactly do the external screw on sensors measure accurate tire temperature? Seems spinning on a cap outside the tire in the ambient air couldn't provide an accurate tire temperature could it?

You are missing the whole point of having a TPMS. You measure accurate tire pressure with an external gauge prior to the tires heating up. The TPMS is just to alert you of a tire malfunction caused by low/high pressure or temperature. Knowing accurate tire pressure going down the road is redundant as it changes with speed, altitude, temperature, road conditions....ect.

Ron

Effy wrote:
How exactly do the external screw on sensors measure accurate tire temperature? Seems spinning on a cap outside the tire in the ambient air couldn't provide an accurate tire temperature could it?

You are correct, they do not measure accurate tire temperature. They are simply measuring the ambient air temp at the end of the valve stem plus any heat gain from the sun on the black sensor housing. The only benefit is that if your brakes are overheating (from over-use or a problem with the drum/caliper) the heat would be transferred to the rim and the ambient would increase, which could possibly be detected by the sensor.

The TPMS is simply a relatively inexpensive tool to provide additional info to the driver and is not designed to provide precision temperature and/or pressure measurements. A system to do that would be significantly more expensive that no one would buy.

Lou
05 Travel Supreme Envoy

How exactly do the external screw on sensors measure accurate tire temperature? Seems spinning on a cap outside the tire in the ambient air couldn't provide an accurate tire temperature could it?

Between gauge pressure and TPMS always a few psi difference with TPMS being less. Old fashion and digital gauge usually within a PSI or two, with digital gauge reading to 0.1 PSI if you believe it.

Unless the TPMS detector is mounted on the wheel rim I am not sure what temperature other than surrounding air you are measuring. We use a IR gun gauge at rest stops to target tire temperature.

Read below to understand why we use a TPMS which at one time we thought was an unnecessary expense. Now it is like our American Express card in that we do not leave home with out one.

TPMS Thread

Tom/Barb wrote:
how accurate are they? worth the 300 price tag?

Yes I do realize one answer reflects the other.

You can change the batteries on the TST Model 507 (not the model 510). The downside with the flow thru sensors are they are physically larger. If install correctly and not over-tighten, the standard sensors do not leak so you don't need to remove them too often. The only time I remove the sensors is when I experience extreme ambient temperature changes (winter to summer) and when I put the rig to bed for the winter. I have also found them to all be within 2 psig of my calibrated tire pressure gauge, but as identified above, your real concern should be any significant changes in pressure and/or temperature. They are probably most important on the toad, because a flat back there will not even be noticed in the MOHO until you are creating sparks from the car dragging on the payment.

Lou
05 Travel Supreme Envoy

Doing a little homework. Anyone have any experience or opinions on these systems?:

Tyre Dog - $229
TireTech - $229
Safeguard - $279
Tire Traker - $289
TST 507 - $299

All of the above systems monitor PSI and Temperature. Most allow for changing the batteries. TST seems to be the best system from what I can find but I would appreciate any input on any of them. Most of the other ones do not have passthrough valves like the TST. That's very handy. But Can you change the batteries on TST?

Make sure if you purchase one, that it not only monitors pressure, but temperature also. If a tire has an internal defect such as a belt slip, there will be a build up of heat well before you start to see visible defects or have a blow out. TST-RV valves monitor both.

TST Monitors