John when I first saw this title, I thought you took your Honda Insight up and down the Rockie Mountains! You may want to report on your fuel mileage when you have the time to do just this.

2005 AWD Escape Hybrid
Best tank trip MPG 39.02 (scangauge II) for 402 miles on I-70, 10.3 gallons used over mostly flat terrain.

Best tank trip MPG 34.6 for E30 for 271 miles along I-80 in Indiana and Ohio.