typically for driving freeway speeds (65) running just under 2000 RPMs is the best. Though with a few of the mods i have done it now seems running at 75 (2200 RPMs) i seem to get a little better mileage. This is of course with the manual transmission.
Sold - 07.5 6.7 Big Horn with lots of goodies.
New Project - 84 Chevy CCSB 12v Conversion, G56 w/271 transfer case, Custom 4 link Coil Over Suspension and much more!!!!!
18 is my best so far with my 08 empty but that is also running at 75 plus with 410 gears
newest toy 14 jeep GC Eco diesel 2008 QCLB sold 2011 cclb Sold 2013 Durango bit the dust 9-04-14 RIP Speedy the 67 vw died a very hot Death 5-17-2010 New toy 1985 crewcab longbed 4x4 conversion with a 93 cummin's and built 518 auto ,hx35 with a 12 wg housing ,366 spring and fuel pin .along with Boost and Pyro gauges and Tach .