Tire pressure question

Great, I just put 44/45 all the way around and don't worry until the TPWS shows, then refill.

 

That may be OK if you reset the TPMS to trip at a higher level. If left at the default, then waiting for the TPMS to light up is waiting far too long, wasting a lot of fuel and tire life.

 

The TPWS seems to notify you about 25 lbs below set air pressure. My PIP is set at 55, I got two nails in two different tires at two different occasions. The tires pressures only went down to 35 lbs each time. Good enough to still drive.

 

My TPWS alerted me much sooner than 25 lb below. Did you mean 25% below? My front tire was set at 42PSI, and it alerted me when it dropped to 38PSI, so approximately a 10% drop. All other tires were at 40/38 from the original 42/40.

 

I am just approximating.

 

What you're reading on the tire is the maximum cold tempetrature pressure that the tire will perform without degrading in some way or another including blowout. It is not the recommended pressure; we tire engineers spend a lot of time performing tire tests for manufacturers to label the most likely pressure that yields COMFORT and safety. Rarely is it the pressure for best performance or long tread life.
Those of us involved in showroom stock racing know that raising the cold pressure indeed improves cornering as well as longer tread life. Generally its not at the maximum rated cold pressure but anywhere from 5 to 10 psig greater than the recommended tire pressures. Its not unusual to run different pressures across each axle as well so experimentation at local autocrosses or vacant parking lots - with permission - is a good idea.
In short the labelled recommended pressures are a starting point, not chiseled in stone.

 

Best post on TP. I have seen.

 

the way all tpms is designed is they trip when pressure is 25% below factory setting. even if you went to a tire shop
& reset the sensors at a higher pressure it will stay at factory settings. only the dealer can set the threshold higher

 

. Yes, I meant 25%. I think the main thing is not when the TPWS goes off but that the low warning is announced long before the pressure reaches 25 or less and one is doing 65-70 MPH on the freeway, especially in the Summer. I think Mahouts advice is very good.

 

As far as I know the TPMS raises an alarm when the pressure drops some percent (likely 25) below what you've set it at. The reset procedure's in the Owners Manual, and any owner can do it, easily.

If you want it to be more sensitive you can do the reset procedure with tire pressure temporarily set higher.

 

I just turned 36k on my OEM tires. Run them @44F/42R - unless I carry my bikes/bike rack then 44all. I rotate my tires every 5k, when I change my oil. The tires are wearing evenly shoulder to shoulder, the ride is compliant(for me), and fuel economy very acceptable. My tires are Bridgestone Turanza EL400-02 in 175/65-15 (max pressure 44#) that came on the steel wheels and I moved them over to the ScionXb alloys.