Tire Pressure - where's the beep?

[MSQ]

As a good newbie (just got the car last Monday) I checked my air pressure and it was at 33, my tires have a maximum pressure of 51. So I changed my pressure to 51 and 48 in the back.



1. At what point is my tire pressure warning gauge going to beep/flash and how does it know?



2. Why all the suggestions to have the back tires with less pressure than the front?



Thanks in advance for the help!



MSQ. 0o0~

[msirach]

<div class='quotetop'>QUOTE(MSQ @ Sep 30 2007, 10:32 PM) [snapback]519657[/snapback]</div>

As a good newbie (just got the car last Monday) I checked my air pressure and it was at 33, my tires have a maximum pressure of 51. So I changed my pressure to 51 and 48 in the back.

1. At what point is my tire pressure warning gauge going to beep/flash and how does it know?
2. Why all the suggestions to have the back tires with less pressure than the front?
Thanks in advance for the help!

MSQ. 0o0~
[/b]

We picked up the new 08 Black Touring #6 yesterday with 3 miles on it. We drove 1/4 mile and stopped at a gas station. I raised the pressure to 50# all around. I didn't even notice the tire rating. I looked tonight and see that it is 51 psi. They were Bridgestone Turanza EL400-02: 195/55/16

Psi difference is related to weight distribution. Look on your door post for the factory recommended that has maximum comfort psi deduction factored in.

[john1701a]

<div class='quotetop'>QUOTE(MSQ @ Sep 30 2007, 10:32 PM) [snapback]519657[/snapback]</div>

1. At what point is my tire pressure warning gauge going to beep/flash...[/b]

When you hit the DANGER level.

In other words, it's a warning not a gauge... something you should fear ever seeing, since that contributes to accidents.

The mandate requires illumination when 25% below the minimum recommended, which is very squishy by Prius owner standards.

[Boo]

<div class='quotetop'>QUOTE(MSQ @ Sep 30 2007, 11:32 PM) [snapback]519657[/snapback]</div>

As a good newbie (just got the car last Monday) I checked my air pressure and it was at 33, my tires have a maximum pressure of 51. So I changed my pressure to 51 and 48 in the back.

1. At what point is my tire pressure warning gauge going to beep/flash and how does it know?

2. Why all the suggestions to have the back tires with less pressure than the front?

Thanks in advance for the help!

MSQ. 0o0~
[/b]

Hi MSQ,

Welcome to PriusChat.

You really should use the Search function on this board. Just search variations of key words or phrases, e.g., in this case, "Tire Pressure" or "Tire Pressure Monitor" or "Tire Pressure Monitor Sensor" or "TPMS".

You should start off with the thread entitled "TPMS Summary Thread", which I've linked for you below:

http://priuschat.com/index.php?showtopic=2...+summary+thread

But to answer your questions directly:

1. I believe the TPMS doesn't beep until pressure drops 25% below its setting. In your case, the TPMS is probably set for the factory recommended pressures of 35 front/33 rear, and will not beep until the pressure drops 25% below those numbers.

If you fill your tires with higher or lower pressure than the factory recommended pressures, then you should reset the TPMS accordingly. I think the Owner's Manual may tell you how to do that. But in any event, the TPMS Summary Thread explains the procedure.

There are also ways to reset the TPMS to beep if pressure drops less than 25%. I believe that the TPMS Summary Thread or several of the other tire pressure monitor sensor threads explain how to do this.

2. The higher recommended pressure for the front is due to the weight distribution of the Prius.

[MSQ]

[quote]

Hi MSQ,

Welcome to PriusChat.

You really should use the Search function on this board. Just search variations of key words or phrases, e.g., in this case, "Tire Pressure" or "Tire Pressure Monitor" or "Tire Pressure Monitor Sensor" or "TPMS".

You should start off with the thread entitled "TPMS Summary Thread", which I've linked for you below:

http://priuschat.com/index.php?showt...summary+thread


Well this is a bit embarrassing... I thought I had read so much on the pressure of the tires that no one had dealt with the TPMS...ooopppsss...



Thanks for the link!



MSQ. 0o0~

[Boo]

<div class='quotetop'>QUOTE(MSQ)</div>

Well this is a bit embarrassing... I thought I had read so much on the pressure of the tires that no one had dealt with the TPMS...ooopppsss...

Thanks for the link!

MSQ. 0o0~
[/b]

No problem. Glad to be of guidance in focusing or refining your search. I guess the most refined search for your questions would be "TPMS" or "Tire Pressure Sensor" --- or else you end up with 40+ pages of thread titles to winnow through.

BTW, as you've probably learned by now, I think the tire pressure warning is in the form of a warning light on the dash, not a beep. And the way it works is that each tire pressure sensor (partially integrated into the valve) sends a wireless radio signal to the tire pressure ECU.

I personally haven't gotten around to resetting or registering the TPMS with my new tire pressures. It's on my 'To Do List' which gets longer every day. Still haven't programmed my VCR to stop flashing "12:00"!

* * * * * *

A couple of related things:

1. If you don't already have one, you should get an accurate tire pressure gauge. I think that as a general matter, round dial analog gauges, which measure 0-60 or -75 psi, with psi increments of 1 or 2 psi, and with an air bleeder valve, are best for your purposes. Accu-Gage's "Professional" series of gauges are supposed to be good consumer gauges. You can pick them up on line or at auto parts stores for around $15.

2. With the TPMS, if you ever change tires you should inform your tire installer about the TPMS and make sure it doesn't change the tire valves or damage the TPMS.

3. With the TPMS, you can't use Fix-A-Flat or similar products. They clog up/damage the TPMS.

* * * * * *

I just noticed that you got a 2008. Sounds great. Did you get the Touring edition? What color?

[MSQ]

A couple of related things:

1. If you don't already have one, you should get an accurate tire pressure gauge. I think that as a general matter, round dial analog gauges, which measure 0-60 or -75 psi, with psi increments of 1 or 2 psi, and with an air bleeder valve, are best for your purposes. Accu-Gage's "Professional" series of gauges are supposed to be good consumer gauges. You can pick them up on line or at auto parts stores for around $15.

2. With the TPMS, if you ever change tires you should inform your tire installer about the TPMS and make sure it doesn't change the tire valves or damage the TPMS.

3. With the TPMS, you can't use Fix-A-Flat or similar products. They clog up/damage the TPMS.

* * * * * *

I just noticed that you got a 2008. Sounds great. Did you get the Touring edition? What color?



I chose the black touring edition w/ the extra option a - freebie from the dealer.

So far I've; reprogrammed the key so it opens all doors, turned off the beep for the seatbelt and reverse, increased the tire pressure and reset the TPMS.



I also "found" through this site the lower compartment in the armrest.



I've never been a part of a group of people who make mods to their new vehicles and I must say it's been great.



Thanks for your help and suggestions, being able to learn from the "elders" has been amazing!



MSQ. 0o0~