[JRMichler]

Today's tank fill calculated to 49.0 MPG, while the dash display said 51.8 MPG. Frustrating because it would have been about 50 MPG if not for the last 100 miles in rain with a headwind. The gas mileage of this truck is VERY sensitive to temperature. Approximate numbers:

0 deg F - 35 MPG
30 deg F - 40 MPG
60 deg F - 49 MPG

My driving technique has been fairly consistent since the first tank. I am not looking forward to next winter's cold temperatures. My driving is about 90% highway, almost all in 55 MPH speed limits. I normally drive about 1 to 5 MPH over the limit. This is a little slower than most people drive in this area, but fast enough that few people get upset. Today, Saturday of Memorial Day weekend, was a little different. I had 8 tailgaters (less than one car length behind me) at various times in a 200 mile trip.

The dash MPG display is about 3% optimistic in 0 to 30 degree temperatures, and about 6% optimistic at 40 to 60 degrees. I was unable to find any way to adjust the ratio. The density of gasoline changes about 3% over that temperature range, which might have something to do with the difference in accuracy.

The truck has an automatic grille shutter. That shutter does not close completely, even at -22 degrees with or without the engine running. I would sure like to know why this is the case. I assume that there is a need for some airflow through the engine compartment at all times.

I was driving in NORMAL mode until 3-14-2022, and ECO mode since then. There is not much difference between the two modes. The largest difference is that in ECO mode and cold weather with the heater running, the engine will shut off at slightly lower coolant temperature.