On Fri, 9 Jan 2015 10:51:08 -0800 (PST), wrote:

Pat:

It's what the dealer told me. Like I said, I 'monitor' my own tires. Besides, how much gas does a tpms save when it allows tires to get 25% below recommended pressure?

If something's important, such as keeping up your tire pressure during fall to winter, you make the time for it, and get a decent gauge.

You can do better than the 25% but it takes work. Pump the tires up
to a value that is higher than your desired pressure and then press
the recalibrate button. Then reduce the pressure to your desired
pressure. In your case, you said that a setting of 41 causes the
warning at 32 - roughly 25% low. Just recalibrate the system at 38 or
39 in order to get a warning at 30.

You make a good point that these systems are not required. I have
always had a good gauge and used it regularly but as I get older I
like that if I get lazy and don't check for a while, it still warns
me.