Tire Pressure Monitoring

bob213 wrote:
My TST 507 is great. It does not include the psychic ability feature that can predict a blow out. If you have tread separation and the tire does not deflate it can not tell you that either. A rapid loss of air pressure or high heat, it reports well.

When we came home and parked we discovered that we had a problem. Tires looked absolutely fine, no pressure loss. But neither of the X-chocks would fit on one side which was very strange since they were pre-adjusted and interchangeable. I looked everywhere for a problem but could not find anything. Took it to a frame shop and they replaced some spring bushings but knew they hadn't found the problem until they measured the diameter of the tires. Two tires on the street side were larger in diameter then the other two on the curb side. But the tires looked fine to them too. I took the rig to my favorite tire shop and the problem became obvious only when the tires were dismounted. Iit took no special skills or tools to see that two of the four tires had lost their integrity. Those tires probably hit something, got damaged, and were ready to blow. Lucky me! And I'm careful with my tires - don't roll over curbs or cut corners and I try to avoid potholes.

So how can I realistically expect a TPMS system to detect something that myself and several experts cannot readily detect. No, I don't have a TPMS system, not yet anyway, but it sounds like a good tool to have onboard. Although tire pressure was never an issue, It might have discovered some excess heat being generated.

Yeah well the physics are:

P1V1/T1 = P2V2/T2 where P=pressure, V=Volume and T-Temp in degrees Kelvin

Since V1=V2 you can drop that from the equation (yes volume may change slightly but we can ignore that)
and P2 is twice P1 then the temp in degrees K would have to double. Like from 270 deg K to 540 deg K and that obviously is not happening. That would be a 270 deg Celsius temp jump since our tires are not running at over 500 deg F. That's what physics says.

My TST 507 is great. It does not include the psychic ability feature that can predict a blow out. If you have tread separation and the tire does not deflate it can not tell you that either. A rapid loss of air pressure or high heat, it reports well.

ajriding wrote:
With campers, towing, truck camper or any high payload weight you will also need to keep an eye out for pressure going UP.

In the desert on hot pavement your tire pressure can double easily.

Now that is amazing. I was told on these boards that when you use X-chocks they can fall right on out when the tire cools a few degrees, because tires expand and contract, it's physics LOL. Now I am :h my head to understand how when a tire heats up enough to increase air pressure as you claim, which I am in no way disputing, it does not swell enough in diameter to release said pressure. One would think it would grow enough to loosely pop off the rim? Go figure LOL. It's physics.

fj12ryder wrote:
IMO the last thing you need is another distraction on the dash, i.e. a TPMS monitor to keep an eye on.

I'm on the other side of this. I found wondering about tire pressures to be a distraction and I was stopping often to walk around and feel for hot tires. The TPMS allowed me to see what the pressure was doing without stopping.

"The rep claimed that the tire pressure is trapped in the sensor when a blow out occurs and that's why it failed to warn us."

I call BS to this statement and as such I would not believe anything that the rep told you.

Most likely had a sensor that was not sending reliable information to the receiver.

With campers, towing, truck camper or any high payload weight you will also need to keep an eye out for pressure going UP.

In the desert on hot pavement your tire pressure can double easily. Tires are usually fine up to double the max pressure stamped on the side just to cover any defective tires.

All my blowouts have been from hot and over-pressurized tires.

A friend has the cheapo internet china bluetooth tire monitor on his and love it, says it works great. However, my tires, at 80 psi, are over the 50psi max that these can do or I would have them. There are higher pressure ones available for higher prices.

Most tire flats, unless you cut it or hit a really big spike, will be slow leaks, or slow psi ramps, so worrying about one or 4 minute intervals not such an issue.

IMO the last thing you need is another distraction on the dash, i.e. a TPMS monitor to keep an eye on. The TST will warn you with a very loud alarm if a tire loses air pressure or the internal temp gets too high. A TPMS may not warn you if you have a blowout, it would depend on what causes the blowout. By the time the TPMS senses a loss in air pressure due to a blowout, it would be too late. But if the blowout occurred due to low air pressure and a resultant build-up in heat leading to a blowout, then the TPMS will do it's job and notify you of an impending issue.

Look at them as additional insurance.

A TPMS will warn you of a tire losing pressure and allow you to get off the road or to a tire shop before damage occurs. It cannot give advance warning for a blowout. But it will let you know that the tire did blow out so that you don't keep driving and ruin a wheel before you realize it.

I have never even had a low tire. But it is definitely worth the peace of mind while driving. People say they don't need one because they always check their tires every time they stop. But tires don't just conveniently lose air for you at rest stops. If you pick up a nail leaving the last rest stop and don't stop again for another 100-150-200 miles, you have no idea that the pressure is dropping without a monitor.

TST 507 here.

We have one and it has real problems. It did notify me of a low pressure in one tire when we got in the vehicle in the morning. It did not warn us before a blow out. It cycles thru each tire, one by one taking over a minute to go thru them all.

If you feel OK with taking your eyes off the road for that long then you might like that TST model. I spoke to their rep at the Tampa RV show and the new models still work the same. There are models that show all the tires continuously and that is what you need IMO. The rep claimed that the tire pressure is trapped in the sensor when a blow out occurs and that's why it failed to warn us. But right now I would not buy a TST.

Hopefully someone out there has had better experience with other brands.