Tire Pressure - Accuracy

[x0swtextacy0x]

how accurate is the low pressure sensor?? either its me making my car roll funny w/ some bounce or its my tires....

ya i kno i could always check the pressure, but im too lazy so i'll prolly take it to toyota an ask them to "check the tires" (and inflate them mwhahah)

[theprodigy79]

the tire pressure warning only alerts you when your tire(s) is/are excessively low/high... It would be wise to keep tabs on your tire pressure (at least check it once a month or so).

[PhreakdOut]

the tire pressure warning only alerts you when your tire(s) is/are excessively low/high... It would be wise to keep tabs on your tire pressure (at least check it once a month or so).

Good advice!

Even if you are too lazy to do it once a month, at the very minimum, you should do it when there is a change in temperature. Colder seasons = pressure drop. Warmer season = higher pressure.

[SPF 0]

I thought (perhaps incorrectly) that it was supposed to illuminate after a 5 Lbs pressure drop.

[theprodigy79]

That's approximately correct... I've heard people say all sorts of things about how the system works, however I'm still under the impression that it goes by the variences in rotation speed during travel (when I asked the dealer they said the same thing)... If it was a sensor measuring actual tire pressure it seems as if that would have to be something implanted in the wheel itself, and therefor would not work for people with aftermarket wheels...

I believe the way the system does work is through variences from the original calibration... When a tire is low, it will require more rotations to keep up with the other wheels... when a tire is too high, it will require fewer rotations than the other wheels at the same speed. So basically it's calculating any severe changes (with a preset margin of error taking into consideration that your wheels are never rotating at the same speed).

[x0swtextacy0x]

thanks guys....i ended up checkin my tires today. buttttt...there was another thread about a real good wheel cleaner that prevents build up of brake dust and dirt for a while.......im not sure where it is, but does anyone know the name of the cleaner??

[SPF 0]

I've had good luck with plain ol' soap, water, and a wheel brush.

[Astro]

Don't waste your money on that, just use soap and water. Also, don't wait sooo long to wash. The longer you wait, the harder it is to take off.

[x0swtextacy0x]

ahh yea i noticed w/ my prev. car.

[DocJohn]

That's approximately correct... I've heard people say all sorts of things about how the system works, however I'm still under the impression that it goes by the variences in rotation speed during travel (when I asked the dealer they said the same thing)... If it was a sensor measuring actual tire pressure it seems as if that would have to be something implanted in the wheel itself, and therefor would not work for people with aftermarket wheels...

I believe the way the system does work is through variences from the original calibration... When a tire is low, it will require more rotations to keep up with the other wheels... when a tire is too high, it will require fewer rotations than the other wheels at the same speed. So basically it's calculating any severe changes (with a preset margin of error taking into consideration that your wheels are never rotating at the same speed).

You are correct in your description of how the TPI system in the Gen 2 Solara operates. This is an 'indirect" TPI system in that it indicates low tire pressure by looking for a variation in the rotation rate between the 4 tires. If one tire has a lower air pressure than the other three, it will have a slightly smaller diameter and therefore cause a slightly faster rotation rate as detected by the speed sensors that I recall are part of the ABS system.

Diirect TPI systems have a true pressure sensor mounted in the inner surface of each wheel and send a radio signal with pressure data to a pressure monitor display.

[slingshot]

WEll, it didn't work on my car. I just checked my tire pressures on all the tires and they were 26-28 instead of the 34 I usually have them at. I should have realized earlier since the car lately has performed a lot worse on turns.

[theprodigy79]

That's the one thing that's wrong with our system... It will NOT read if all tires lose pressure somewhat evenly... It is intended to measure variance against the other wheels, however if there is no variance (ie. if all tires lose pressure at around the same rate) then it will not pick anything up... However, in the systems defense, that is a very rare case (usually one or two tires go at a time)...

[x0swtextacy0x]

thanks guys....i ended up checkin my tires today. buttttt...there was another thread about a real good wheel cleaner that prevents build up of brake dust and dirt for a while.......im not sure where it is, but does anyone know the name of the cleaner??

i found it

http://www.solaraguy.org/viewtopic.php?t=19969&postdays=0&postorder=asc&start=10

but i think i'll stick w/ my mr. clean magic eraser wheel cleaner lol cheaper and easier.

[morganm00]

It does seem like it takes a little time for it to recognize low-pressure. I hit a massive pot-hole the other night and wound up with a big hole in the side of the tire. I drove on it for about a block trying to determine if that thump-thump-thump was the roads or me. Turned out it was me. But the low-pressure indicator never came on in the car ... not sure if maybe it's just not working or it takes a while to notice.

It was still pretty disappointing to have happen since the car is only 3 months old.

[theprodigy79]

It needs to be calibrated properly initially before it will work correctly... one way to determine this is to watch the indicator when you first turn on your vehicle... it should go off with the rest of the test lights... if it stays on more than a second more than the others it needs to be recalibrated.