Over the past 35,000 miles I have averaged 8.3 MPG, 2003 vintage 6.8 V-10 moving a 30 foot Class C, usually loaded to about 13,000 pounds. Every mile, every tank of gas, logged.
You can probably make it a little better than that by driving very slowly, but you are not going to see much better than 10 MPG, even on that rare tank of gas when you got pushed by a 20 MPH tailwind. Current cost is 40-50 cents per mile to move the thing, just gas.
For the past few years, I've been resolving the gas cost issue by making short trips, nearest CG is 15 miles, favorite is less than 100.
But contemplating road trips, I need to weigh the desire of being in the motorhome against the cost of moving it. If I move 100-200 miles a day and stay a few nights to a week at each location, the motorhome economics are not too bad. However, if I need to move 300-600 miles a day, it is a whole lot cheaper to drive my 40 MPG car and spend $100-200 a night on hotel rooms and restaurant meals. If I choose to drive my 20 MPG truck, I can still be ahead with $100 motel stays.
So think about how you are going to use the motorhome, and decide whether your MPG concerns are valid. Economically, it really depends on how you will use it. If you think it is going to save you money traveling, that is questionable.
Beyond economics, it becomes a lifestyle issue. For me, a 4000 mile, two week, $3000 RV road trip has to be weighed against a two-week escorted tour, trip to Europe or Asia, two week cruise at those costs.
If you are not into other modes of travel, and you think you want the RV lifestyle, don't worry too much about MPG. If you are thinking of RVing as a cost saving approach to road tripping in the U.S., you do need to consider MPG, rate of progress, length and costs of stays.
But then, not everyone is willing to make a road trip in a 40 MPG car.
Tom Test
Itasca Spirit 29B
