I'm happy to report the TPMS works as advertised.. On the day before I went on a 300 mile trip we were out shopping and the warning light came on when we left the grocery store for home. Looking at the tires nothing looked wrong and the car was driving normally. I got out my tire pressure gauge and sure enough the driver side rear was down to 18 psi. Looked at the tread and lo and behold there was a screw imbedded right in the middle. Got the tire repaired and made the round trip from Sacramento area to San Jose with no problems. Could have been a totally different experience had I not been warned! :cheer2:
It saved me on a screw just like you. I also could not tell which tire was low until I used a pressure gauge.
I think I read somewhere, that until the PSI drops below 10ish, you won't easily be able to see it with your eyes. How true that is, I have no clue, and it's possible for some that use higher PSI, you might notice it sooner.
Depends on the tire and the observer. Some tires, properly inflated look ‘bagged’ to me. IIRC, the TPMS will alert you to a 10-psi drop in pressure, which is usually sufficient to get a 'screwed' or a 'nailed' tire to the nearest tire shop, although I've not (yet) been screwed or nailed in any of my TPMS equipped vehicles. I've seen people who claim to be able to 'see' as little as a 5-psi drop in their tire pressure, but I'll admit that I personally have to rely on a tire gauge (or the TPMS) to tell the difference between 42-PSI and 32-PSI on the Prius tires. YMMV.
If you want to do a quick and dirty pressure checks, rest your fingers on top of the tire and pressure your thumb into the sidewall. You can try it with different pressures in two tires to see how good your thumb is calibrated. Truckers used to (still do?) whack their tires sidewalls with a mallet or hammer and judged the pressure by the amount of rebound. Not precise but an easy way to spot a tire on it's way to being flat.
When my brother was driving a truck, I noticed him carrying around a miniature metal baseball bat for just that purpose. When you've got 18 wheels to check, and 8 of them change every time you drop off a load and pick up a new one, I can understand not wanting to actually measure each one...
yes it does. My only beef when you turn car on it takes a few min for it to check in, so if you got flat which deflated while parked, you may chew your tire by the time TPMS kicks in. You still have to go around and do visual inspection before you get in. Don't ask how I know this.
Not for me, when the tire pressure light kicks on, it kicks on within 5 seconds after powering up the car. I wonder when self inflating tires can be mass produced.
Here's something where I admit upfront my P.O.V. is probably...most certainly wrong. Inflexibility and stubborn "old age" makes it difficult for me to appreciate TPMS. The thing is, TPMS becomes such a pain when one desires to change either rims or tires, that despite the possible advantages? I long for the old days that won't come back, when most vehicles did NOT have TPMS. I know, I know, this is an arguement I can't win and shouldn't win. But I'm very observant as to my tire pressure. That doesn't mean TPMS couldn't help me, but I think a situation where it would be of great value to me would be rare. I agressively check my Tire Pressure pretty often, and keep a visual eye on how my tires look almost every time I approach my vehicle. Again, hardly an arguement against TPMS...but... I just hate the idea of rather temperamental and expensive sensors now needing to be used, sensors that need to be replaced or duplicated with the changing of tires or the replacement of rims. From time to time, I don't mind having an opinion or P.O.V. from which I know I can't win. TPMS is one newer "requirements" on new vehicles that I have yet been able to embrace. Give me some time...maybe someday a nail or screw will convince me I need this level of electronic Nanny protection. ...Maybe....
how does tpms work ? where's that function on the car ? can you see on the display screen all 4 tire pressures ? or does the icon only come up when your tires are flat ??
I like a good TPMS system, one that allows you to read tire pressure form your instrument panel. Even the Prius system that hides that information from the driver has value. But, to add to your list of objections, the TPMS units in the wheels have non-replaceable batteries. After around 6 to 8 years the TPMS sensors will need to be replaced if you want to still have TPM$. For the limited value the Prius system provides I wouldn't consider replacing them. On our other 2 cars that allow tire pressure to be read from the dash, I would consider replacing them if I still have the cars when the TPMS batteries die. On the Corvette forum, a couple of people have cut their TPMS sensors open, replaced the batteries and repotted them, so it's not exactly true to say the batteries aren't replaceable. This may be of general interest to some http://forums.corvetteforum.com/c6-tech-performance/2834468-c6-tpms-battery-replacement.html I have no idea if our Prius sensor batteries are as easy to replace,
After seeing that youtube video of scraping out the interior and puncturing the battery I'm not planning on trying that "fix". I probably won't have a choice on avoiding TPMS but I at least know I can just leave the battery dead and go on driving the car with TPMS disabled (with or without disabling the dash light).
I'm with you, I won't do mine either but always like to see how people solve problems that the manufacturers would have you believe are insolvable.
I know. I can't win an arguement against them. Dealing with them can become an expensive pain in the @$$ though, but a system that notifies you if your tire pressure drops is hard to argue against. It's an "old mans" invalid arguement. But I do remember literally decades and decades where we all survived pretty well taking the responsibility of checking our own tire pressure. But there is no going back. TPMS is here to stay.
You can find the sensors online for reasonable prices if you know where to look. Even some salvage yards will have them, I'd imagine. There's 2 manufacturers of the Toyota TPMS. The Prius ones are made by Pacific (possible the other company makes them too), and are model: PMV-107J. I bought an extra set on ebay for about $50-60 earlier this year. Of course, you'll also get stuck needing the kit, but most tire shops sell them for about $3-5 when they install. As we know, once you get them installed, you have to update the ECU for the new IDs. For those of us with a TechStream cable and software, that's not an issue. After this winter, and my winter tires need replaced, I'll have to decide if I want to keep doing the winter tires or not. I agree that there really is no helpful information from Toyota on the TPMS, unless you have TechStream active in your car as you drive. Updating the sensors is also a headache, as some other car makers have made it so the IDs will update automatically by their ECU. That would be way more beneficial.