I thought I would share with you my actual mpg for my western trip in my Fleetwood Montera 25K E450 V-10
We left Raleigh, NC and travelled to Mt Rushmore, Yellowstone, Grand Teton, Bryce Canyon, Zion, Grand Canyon North and South Rims, Monument Valley, Canyon de Chelle, Albaquerque, Santa Fe and then eastward on I 40 to pigeon Forge and then home.
We were gone from Labor Day to October 13 and travelled 6,264 miles and we purchased 702.2 gal of regular fuel for overall mpg of 8.92. We were not towing anything.
During this trip we used the generator a good bit at Yellowstone, Grand Teton and the North rim as well as Canyon de Chelle in addition to lunch stops. I was surprised that a lot of the regular gas was 85 or 86 octane rather than 87 octane we have here in NC.
The majority of the trip was at 60-62 mph and the tach showed about 22-2300 rpm except for I 90 and I 15. 90 is 75 mph and 15 from Sault Lake is 80! The fastest I went on these highways was 70.
My starting mileage was 3800 mi so the engine was not really broken in and now I am over 10k and think the flat country mileage with neutral wind and not towing is 9.2 to nearly 10. I did not have the wind at my back at any time so I did not benefit from it.
I guess this mileage is the norm?
I wish the Ford cruise control fed more gas rather than allowing the down shift but I guess that is the nature of the beast.
Tow haul was a great friend on the mountainous roads and I used cruise sparingly. If I was using cruise I gave it a little acceleration on the hills (up to 2500 rpm) and allowed it to lug down to 2000 rpm to avoid the downshifts