starstreak

I had my tire pressure warning go off. Needsless to say, it doesnt tell me what wheel so I checked them all. All my tires are down to abour 27psi. Normal psi for the summer tires is 33? While I thought it was strange for me to see the tire pressure warning go off got 27psi, it got me thinking, do you know what kind of effect this could have on gas milage?

MadDawg350

I think the TPMS warninig goes off when the pressure drops approximate 10-15% from the recommended set pressure which is 33psi. And of course, when the tire presssure is low, your mileage will be adversely affected.

socalJD

Low tire pressure will negatively impact your gas mileage, and also cause uneven wear on your tires. Since the rwd 3GS has 18" hi perf summer tires that cost >$300 a pop, you'll want to keep an eye on the tire pressure. . .

rominl

iTrader: (4)

it triggers around 28psi i believe. and yes, it will decrease your mpg like socalJD said

Cut-Throat

Can't you set it for any pressure you want?



- I think I remember going through the Tire Calibration procedure last year when I got my car. If I remember correctly, you pump up your tires to your desired Air Pressure than run the 'Tire Pressure Calibration' procedure and it 'Memorizes' your current pressure. Then I believe the sensor will go off when it drops off below that.

Jace7

Yes, you can set the number to anything. I think normally from the factory they are set at 33.
The TPMS goes off when it fluctuates 3 lbs. up or down, from whatever you have it set at, in most cases it's set at 33.
Mine never fluctuate more than .5 lbs, becuase I got the nitrogen running through them.
Good for areas where the climate goes hot to cold.
Not really as necessary in HI.

starstreak

I saw that nitrogen system on a car show on tv. Looked like a good idea. But I guess since HI doesnt change in temp as much as the mainland we dont really have the dealer for that. I guess first chance I get, I'll inflate those tires.

BurgBoxstr

It can't go off above the pressure b/c the spare is inflated to to either 50 or 60# in the GS (can't remember specifically). But the low pressure in my spare did set it off the TPMS warning (27# when I checked it).

Plus in my GX, the dealer once set my pressure to 42 when it should be 31 . Only sensor that went off on the way home was my butt's bounce-o-meter

rominl

iTrader: (4)

this is really confusing. does the spare tire (donut) have a TPS in it as well or not?!

Cut-Throat

Mine doesn't have one.

mitsuguy

iTrader: (2)

15%...

the amount a tire 5 psi low will increase fuel mileage...

on average of course...