Tire Pressure Monitor System By Tst - W/6 Sensors - No Flow

Looking forward to camping season I purchased this tire pressure monitoring system in the winter but didn’t try it out until summer well past the return period. When I did try it I found the readings were 4 psi off as compared to 5 other tire gauges. I have a Milton 976, an Accutire digital, an Astro Pneumatic digital gauge and filler, and a Viair mechanical dial gauge and filler (reads 2 psi high), and a no name pencil (reads 2 psi low), gauges all of which read within 2 psi of each other except the reviewed system which was 4 psi lower. I tested my gauges at 30 psi, 50 psi (my trailer pressure) and 65 psi (my truck) and the error didn’t vary with pressure for each gauge including the TPMS. All 5 sensors on the TPMS were reading low so the problem is probably in the display unit. I called TST and told them about the problem and was told that it was normal for the system to read off that much. I informed her that it should read plus or minus 1.5 psi. She asked where I heard such a thing so I told her it was on page 10, the specification page, in the manual. So she said send it in. I did on my dime and a few weeks later got it back with the note all reading was within specs. This is obviously not the case as other reviewers noted. There is no branding on the device at all and the only branding is on the box which has is no indication of where it’s made. The chips in the device are made by Samsung so my guess is Truck System Technologies purchased this from South Korea and have no idea how it works. A proper system should have firmware where the company or even better you could put in a correction factor to make the readings correct for each sensor. A 4 psi error is probably not that big of a deal but a device that has a digital read out with a precision of 1 psi should be at least that accurate. A 4 psi error is a lower percentage for a 100 psi tire than for a 50 psi tire which I have. Each sensor cost 50 bucks and with a total cost of around $300 with 5 sensors I expect to get accurate readings, at least as accurate as that 12 dollar Accutire gauge.. Why put a digital display on it if it’s wrong? Maybe just an “idiot” light would be more appropriate. It does the job but you will need to set the alarm points with the error in mind or you may get annoying alarms as the temperature changes a little in the tires. Use a proper tire gauge to check your tire pressure and note the difference on the TPMS then you can probably rely on the reading as they did seem consistent. You can’t use the TPMS to fill your tires because it doesn’t update in real time. I can disconnect the trailer and the reading will still be there for quite a while after driving off. Ironically on my first trip after sitting in a campground for 4 days it sure enough alarmed and I found one of the tires had very low pressure apparently caused by the valve stem sensor not screwed on tight enough. The anti-theft shells on the sensors are not effective since you can use your fingers just behind the shell and remove the things. On the plus side I did get good range on the sensors and had no problems reading the rearmost tires on my 27 ft. travel trailer. I didn’t check the accuracy of the temperature readings as I had no means to read internal air temperature other than this system. Some tire shops may have a calibrated standard pressure gauge that they use to test their own gauges so maybe you could get yours tested there. Don’t trust gas stations gauges to be accurate since they may have been dropped many times and may spend their time out in the weather. I think a Tire Pressure Monitoring system is a good investment since it could save you from a lot of trailer damage if an unnoticed flat tire comes apart or worse if a wreck happens. This system is certainly better than nothing and does the job. I just wish it was accurate.

I give these two stars because they do work. But, you are likely going to need the repeater to capture the sensor signals and pass them up to the cab of your truck. Mine works without the repeater but only if the monitor is down in the cup holder. One would expect it to work better if held up at window height but it doesn't. A larger issue I found is that the sensors are substantial in size and weight and bob around a lot due to wind turbulence and the centrifugal force of the spinning wheel. The result is 1) broken valve stems if the valve stems are not new or highly flexible or a metal or reinforced type; 2) badly marred aluminum wheels if you have them. I experienced both problems and stopped using the sensors (mostly to prevent flat tires from broken valve stems). If/when I get stronger valve stems I may start using the sensors again, but will remove the outer shell that is supposed to make them harder to steal. Even if you tighten them snugly on your valve stems with the included special wrench, they can still be removed by hand by wrapping fingers around them to grip the nut-like piece that screws onto the valve stem. With this outer shell removed, the sensors will be smaller and lighter and I think less likely to break older rubber valve stems.This said, I'm not sure there is a better system other than one with sensors that mount inside of the wheel.Accuracy of the sensors is surprisingly good. All were within about +/- one psi of actual.The read-out of four tire pressures takes considerable time, 10's of seconds. As a result you won't have very quick notice of a loss of pressure, but surely quick enough to prevent a blow-out from excessive heat.UPDATE: My above comments hold, but I did find a work-around for the dropped sensor signals if the receiver was not held in the right place. First, I replaced the little stubby antenna with a five inch 2.4 GHz antenna and that helped a lot. Still, the unit was a bit fussy about location (even the overhead sun glasses pocket which provides near line-of-sight to the trailer tires does not work all that well) so I tried a remote antenna. I found a 2.4 GHz high gain antenna with an 8' coax and put it in the back window of the cab of the truck. The thin coax runs up to the unit and the unit sits in the console. This antenna is about 9" tall and has a magnetic base. It's probably a 7 dbi gain antenna. I simply propped it up on top of one of the rear seats for testing. It is working great and I will soon prepare some kind of permanent support for it. This remote antenna was a lot less costly and easier to install than the $70 repeater that the company recommends. That unit requires 12V and would involve a more difficult installation.

I have owned this system for over a year now, just came back from a 4 week trip in our 5th wheel and I have to place a review on this system. Unreliable is all I can say. Before I left on my trip I replaced the batteries in all of the 8 sensors I have and while traveling I randomly loose the sensors while driving. One thing I found was if you travel faster than 65 MPH sensors that were locked in will just fail out. Also heat is an issue, at greater than 90°F- tire temp- sensors will randomly fail. I paid a lot of money for this system and it is utterly unreliable. I wish I could return this system but it is over a year old-that being said the unit usage has only been about 3 months of traveling which is about < 6,000 miles.