VIDEO - Tire Pressure Monitoring Systems

VideoThis short video by the Tire Industry Association explains what your tire pressure monitoring system (TPMS) does and why it is important to know when any of your tires are underinflated. Aside from the safety benefits, the TPMS system can  decrease irregular tire wear, improve your vehicle’s handling, reduce braking distance and better your fuel economy.

Too bad this didn't come with a corresponding explanation.

To clear up any confusion, this was a US video, and that is the jurisdiction that requires TPMS on all new vehicles after 2008, not Canada.

I've had the system on a vehicle and it was a real pain, it went off 3 or 4 times telling me a tire was low, I was back and forth having the system checked out.  I think I was in there 3 or 4 times, and not once was there a low tire.

Human nature being what it is, when an alarm is continually give false positives people tend to ignore the warnings and then when it's genuine chances are it could be ignored.

The system has two parts, the receivers and the dash interface is built into the vehicle, then each wheel is affixed with a sensor.

Something I didn't think of was buying a second set of rims for snow tires.  Being that the sensors are installed on each wheel, inside the tire I had to purchase 4 for my extra set of wheels.  So add $350, $400 to a spare set of wheels for your snow tires.  Yikes !

Thought I would share some random thoughts on this.

My first experience of TPMS was far from positive - a company I worked for operated a 2008 Ford Windstar, and having parked it only hours earlier I didn't bother with a walk-around when I jumped in again and drove off later. Travelled about 30 meters - no warning light on the dash - but it was obvious something wasn't righteous with the vehicle and what do you know, the right front tire had picked up a nail and almost completely deflated. This is the kind of thing that makes you question the value of such systems.

My next experience of TPMS was quite the opposite - I was driving my 2012 Ford Econoline E-350 bus, with eight passengers and associated luggage on a trip from Whistler to YVR. All seemed good, yet approaching Squamish the warning light turned on. Nothing was obviously wrong, the vehicle was handling normally, but of course I pulled over to see what might have triggered it. Tire temperatures and eyeball check didn't indicate any problems, but when I then put a pressure gauge on the tires it turned out the right rear was down from 80 psi to 60 psi. I corrected the pressure at the first gas station a couple of kilometers down the road, listened carefully for a leak (couldn't hear anything) and so I completed the journey.

Having discharged my passengers, as soon as possible I checked that tire again, and sure enough it had lost a few pounds - obviously a slow leak, but these things don't fix themselves; by the time I got back to home base (about 200 kilometers travel since ensuring the tire was back up to 80 psi) the light was on again, and a pressure check confirmed it was down to around 62 psi, so I took it into the shop where they found the problem and fixed it (once again, a nail through the tread). This is the kind of thing that makes you think these systems are the greatest thing since sliced bread ...

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I'm probably a bit more persnickety about this stuff than most; my Dad worked most of his life for Goodrich and Goodyear, and my younger brother worked for Michelin. Plus which, I've had the experience of having four brand new tires installed on a car, only for the right front to blow out on the highway at 80 mph ten minutes later; remember the Firestone 500's? Plus which, I've also had a right rear blow - and in each case, I mean disintegrate rapidly, not just lose pressure - at a similar speed. Most drivers probably don't ever have this happen, but such is life.

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Can TPMS be relied upon, then, instead of human monitoring? Heck, no - it's only likely to warn you if one or more tires is significantly underinflated (or overinflated I guess, but that's pretty unlikely). I just got back from three weeks' vacation and fall has arrived; sure enough, when I checked my Econoline, all four tires were down by 5 to 7 psi just from the change in ambient temperature. If you haven't checked your tires in the last month, then you can pretty much bet that your vehicle's tires will be similarly low on pressure. And a visual check hasn't been much use since we all had bias ply tires on our vehicles forty odd years ago.

So maybe take a look at that, and anticipate that by December your pressures will have dropped again, without any air loss having occurred. That would be my advice.