[timbocool]

Temperatures have been dropping in the Boston area over the last few weeks and of course the temp affects tire pressure. I noticed the front tire of my daughters car looked a little low so I checked and sure enough all of her tires, my son's, my wife's and mine on the TLX were low. I filled all to recommended pressure. A couple days later before driving (tires still cold) I scrolled to the tire pressure readout screen and all of my tires were reading 37-38 lbs. I checked with my good ($$$) tire gauge and they all read 32 lbs, just in case I used a different gauge and that one said all at 31-1/2 (close enough) so bottom line I wouldn't trust the read out the car gives for tire pressure.

 

[SameButDifferent]

Is the readout accurate when the temperature isn't so cold? Or would you just not trust it ever?

 

[TLX2014]

Watch the TPMS readings after starting the car and driving for the first half a mile to see it they change. The feedback on my 3G TL was pretty instant but I have seen reports that the sensors may not give the current pressure until the car has been in motion for a short distance. I will try to remember to check my car tomorrow to see if it changes.

 

[explicit_tl]

that's why i always have a cheap gauge in my glove box, always been used to checking it manually.

 

[15MTLX]

Watch the TPMS readings after starting the car and driving for the first half a mile to see it they change. The feedback on my 3G TL was pretty instant but I have seen reports that the sensors may not give the current pressure until the car has been in motion for a short distance. I will try to remember to check my car tomorrow to see if it changes.

Yes you need to drive over 60 km/h (35 mph I think) for a few minutes before the pressures refresh.

Did you check the tire pressure immediately after you saw 38 psi on the TPMS? It could be the difference between cold and warm tire pressure.