In a cross country trip spanning from Illinois to Southern California and back, our Jeep Liberty CRD averaged 29.17 mpg (hand-calculated) with its new General Grabber HTS tread...

 With a route that took us through the Rocky Mountains on our way out west (I-70 and I-15), and through the desert and high plains on our way back (I-40 and I-44), we think the Jeep did pretty well, considering the weather conditions it faced. Surprisingly, the worst tank average came from flat land driving through Kansas and eastern Colorado (no mountains), which was 25.92 mpg with the cruise set on 70 mph, but with 20-degree temperatures and gusting northbound winds blowing us all over the road.

 What we didn't expect to see were the figures produced on the very next tank: 30.27 mpg while traveling through the steep grades of the Rockies.

 Once out of the mountains, our most efficient tank came as we progressed from the high desert into the low desert in SoCal. It came out to 32.13 mpg.

 All in all, we covered 3,700 miles, stopped nine times for fuel, beat the 30 mpg mark three times, and achieved in the neighborhood of at least 28 mpg at seven out of our nine fill ups.