Tire Pressure Sensor in Spare?

Porsche does, and I suspect some/all of the luxury brands do.

 

Which is totally understandable. ...and I think I've seen where it's general consensus that the TPMS systems wont give you a very exact pressure. They'll let you know if you drop below the threshold, likely to be 25 or below, but for now they can't be used to monitor the tire pressure in an exact way like some of us might like to do.

 

Thanks! I was going to look for something like this. :rockon:

 

My wife's Caddy also displays psi for each tire, and it seems pretty accurate. I assume the Prius sensors are not very accurate, so that even if all tires were at the same pressure, each sensor would report slightly different numbers. If those readings were displayed, it would drive us nuts and we would complain.

It seems that for a few bucks (okay a few hundred bucks) the sensors could be more useful. What does Lexus do?

 

If the Gen III TPMS is like the Gen II's, then the threshold is 25% below the psi that the TPMS is set for (note that you can trick or monkey around with the TPMS so that the threshold is effectively lower than that 25%).

So if the TPMS is set for 40 psi, then if any of the 4 tires drops to 30 psi, then the TPMS warning light icon should go on.

 

Which isn't very useful...unless you drove around with a Techstream device in your car...

 

Maybe Gen IV will show this useful info.

If the past is any indication, Toyota doesn't seem to favor mid-generational changes. E.g., it took Toyota a whole generation to move the driver seat's furthest rearward travel point back 2.5 inches. IMO, they could have made this change in 2005 and it would have cost no more than a few pennies or dollars per car.

 

If I'm honest, I'll admit I'm lucky to check anything unless I think about it. I guess I check tire pressure once a month, if I'm lucky. I tried to regularly do a walk-around each morning before getting into my car (walk around the car and look at the tires) - that lasted about a week. Anyway, a tire has to be way down in pressure before you can see it.

This brings up my new definition of an optimist. It's the guy or gal who wrote the Prius manual and said: "Make sure to check the inflation pressure as part of your daily vehicle checks (p439)"

Anybody out there checking their tire pressure daily? Weekly? Be honest

 

I have been checking them about every other week but now that I have TPMS I will never need to check them again. Isn't technology wonderful?

 

What you just said makes perfect sense to me AND it's precisely what I thought I was going to do......until......I saw where the manual says (p439) "The tire pressure warning system does not replace...daily...tire inflation pressure checks." Hmmmm... back to that again, are we?

I'm not complaining (what!?!? ME COMPLAIN???), just being cute. I know it's important to ensure proper tire pressure. As my niece's husband (02 Prius) told me: "If you want good mileage on your new Prius, keep the tire pressure way up." I guess high pressure = good airodynamics? </gulp!>

 

Reminds me of a freak-incident that happened to my car a week ago as I was puilling out of my driveway. I heard that familiar scraping sound sound that tells you you're dragging a tree branch or something under the car. I stopped to check it out - no branches, but the plastic cover that forms the forward part of the (right front)wheel well had been torn out and was dragging. What?! How was this possible, I hadn't run over anything. And why didn't I hear it before?

Took me a while to figure this out... I had turned my car around in the driveway the night before. I remembered extending a little past the concrete onto the grass, before I backed up to complete the 3-point turn when I heard a sound like rubbing against a branch or something. Paid no attention to that.... heh heh. Well, I went back to that spot and saw a plastic sprinkler head sticking up - apparently undamaged - and next to it, the missing plastic retainer pin that holds the wheel well cover on. It was easy to remount the cover - looks good as new.

Here's the strange thing. If the sprinkler head had been 1/2" higher, it would have broken off and not touched the cover - if it had been 1/2" lower it would have cleared the cover, again no problem to the car. It had to be EXACTLY that height to hook the cover and tear it off !!!! I imagine this freak event will never be reproduced again in the next 10 years by any Prius (let us know if I'm wrong </grin> ). Gremlins?? Bad stars??

 

Wow how freaky is that. The same thing happened to me just yesterday. Just kidding. :banplease:

 

My 2005 GMC Yukon Denali has TPMS that displays psi for each tire.