Cptnvideo wrote:
We tow a 42' 5th with a Ram dually. 27,000 pounds going down the road and 13'5" tall. I usually don't pay attention to the fuel economy as it really doesn't matter (kind of like asking what the fuel economy is of a $300k boat - if you have to ask about fuel economy, you have no business buying the boat). But when I do check MPG towing, it is between 8 and 9 MPG.
Not a $300k boat (well, new they would both be in that range) but we sold our 1.5MPG boat to buy a similar size boat that got 6-10MPG. We gave up top end speed but when you are doing thousands of miles of motoring, it made a lot of sense, especially since marina fuel prices are typically $1/gal higher than on the road.
Also don't run at 75mph with the RV because you can pretty much see the needle on the fuel gauge moving. We aren't in any great rush, so 55-60mph is fine so long as we aren't holding up traffic.