Back when we had our MCI bus conversion, I always felt like the red headed stepchild in the family, because every bus owner I knew claimed he got 8, 9, or even 10 miles per gallon, while I was lucky to squeeze a shade over 6 MPG from our old 8V71 Detroit diesel. On flat land, with a tailwind, we occasionally got a tad over 7 MPG, but there’s not all that much flat land in America, and we all know that tailwinds are about as elusive as honest politicians.
When we bought our 2002 Winnebago Ultimate Advantage, with its 350 Cummins turbo diesel and Allison six speed automatic transmission, RVers with similar rigs told me that they got 8 to 10 miles per gallon. Our rig only had 33,000 miles on the odometer when we bought it, so when our Silverleaf VMSpc engine monitoring system reported that we were only getting 7 MPG, everybody told me that once we got 50,000 miles on the clock and the engine was broken in, we’d see an improvement. We haven’t.
Greg White has the same engine and transmission, on the same Spartan chassis, on his American Eagle diesel pusher. Both rigs are 40 feet long,and weigh close to the same. Greg’s coach is a 1999, and has more miles on it than ours does. We tow a Ford Explorer with two kayaks on the roof, and Greg tows a four door Dodge Dakota pickup with a camper shell on it. On trips we’ve taken together, Greg consistently gets a mile or more per gallon than I do. Why is that?
I know that driving habits are usually the single-most thing that affects fuel mileage. On the open highway, I usually travel at about 62-65 miles per hour. I’ve tried staying at 55, but to be honest, I have not seen any significant difference in our fuel economy, and I get tired of the eighteen wheelers climbing up my tailpipe.
Don’t get me wrong, I’m not complaining. Though I’d love to get 10 miles per gallon like so many RVers claim to do, my home on wheels still gets better mileage than the houses most people I know live in!
But I am curious; what do you drive, and what kind of mileage do you get? And what is your average cruising speed? Have you done any modifications to your RV to increase mileage or horsepower (Banks exhaust system, engine chip, high performance air filter)?
Thought for The Day – None are so old as those who have outlived enthusiasm. ~ Henry David Thoreau