So I am constantly monitoring the onboard mpg readout with every fillup. I basically drive the exact same areas which is a mix of city and highway. Not a lot of long trips yet, basically to work and back which is about 15 minutes. When I got the truck I was at 21-ish for an average and after a few tanks I was consistantly getting 23.8-24.5. The last tank I got 21. I thought maybe crappy gas at 7-11 so I avoid it now. I filled up at my Mobil the last tank and averaged 20.5. I thought to myself something isn't right. I checked the pressure on the tires and all 4 were roghly 35 psi. The Michelins say 44 psi max so I inflated to 40 on all 4. Half a tank later driving around the same roads I am back at 24 ish. It proves to me that I need to check the pressure more often. It coincides with the weather drop to freezing so I assume that with the winter temp change I just needed to fill them and keep an eye on them.