New Aspire RBQ only about 20% loaded with our stuff. Towing a Honda Odyssey (~4200#). Kept speed 60-65mph, 1600-1800rpm. Trip from MA to Middlebury, some decent hills in Western MA and NY. No significant wind. Average according to Spartan Message Center about 9.2. Not enough fillups yet to get a comparative calculation. Other owners report high 8's.
Previous coach a 39' Fleetwood Discovery Cat C7 330HP. Compared to Cummins ISL (450) on Aspire, Discovery rig has 30% less torque, 30% less HP, significantly lighter, no tag, no emissions systems yet substantially lower mpg. About 6.8mpg over 14K miles with same toad, etc.