Picked up my 2500 159 high on Fri night. It was cold out, upper 20's low 30's. Dealer warns me that its cold out and tpms will signal low pressure. I'm not new to it being cold out and tire pressure being lower. So, I drive off the lot with it signaling low pressure. Yesterday and today it was in the 60's. Still signals low pressure, so I check them. All are at or near 70 psi cold. Door jam sticker says front should be 65 and rear 80. All tires themselves say 80 cold. Which is it?