Guys, you can't be fussing over fuel milage when you drive a bus.
JC
Sure I can. In fact mileage was even more important to the fleets that ran these machines.
For example, this Bounder we been pushing around the last 7 years, we have accumulated over 50K miles. Most of that distance was foot to floor 70-75 mph plus, whatever she would do floored, and I averaged 6.5 - 7 mpg. Not bad. However, the last 10K miles or so I've backed off on the throttle, and found that as long as I keep it under 65 mph, I'm solidly in the 9+ MPG range and have made 10+ MPG if I don't go over 55. And yes, 55 is tough.
Had I driven 60-65 the entire 50K miles, I would have averaged around 9.5, and burned 5263 gallons of fuel. And at at average cost of $3 gallon, would have spent $15,789 in fuel.
At 6.5 MPG, which was more often the norm for most of our ownership, over 50K miles we would have consumed 7692 gallons of fuel, at a cost of $23,076, exceeding our purchase price of the Bounder itself. Slowing down could have saved us $7,287. As you can see, a 1 to 2 mile per gallon improvement makes a HUGE difference when your starting from less than 10 MPG.
So ask yourself, would it have paid for me to drive 5 to 10 MPH slower that whole time? If I figure a good half that mileage we spent $4 gallon, not $3, the savings are closer to $9,000. And thats about what I feel my foot to the floor attitude cost us. Do the math at $6 gallon, which could happen, and the cost differences are even more polarized. Also, at lower speed the rig rides smoother, I dont get so tired, I'm more relaxed, the engine runs cooler, as do the tires and tranny and everything else. So its more than just fuel economy that changes.
I dont know about anyone else, but thats a lot of money. Thats a trip to Alaska I would like to take. Or an engine out overhaul or some other big upgrade deal. Dont get me wrong, I like winding it up too, and still will if and when I feel like it and have money burning a hole in my pocket or a bad case of getthereitis. But don't gripe or complain if you see me tooling along in the right lane at 65 per either.
Ultimately, if a Bus conversion can get 10 MPG, and more, its much easier to sell to the naysayers and treehuggers who would like to believe we all out there guzzling it down at some more ridiculous rate. For most people looking at our huge RV dragging a car along, 5 MPG just sounds totally awful ("

Ewwww" response). 7 MPG seems to be much easier for most people to accept ("

thats not bad" response). 10 MPG makes most people speechless ("

" response). More than 10 makes a lot of people call you a liar ("

yeah right" response).