With all the other costs, including the initial outlay of money, fuel mileage is pretty low on my list.
Say you pay an extra $20,000 for something that gets 4 mpg better mileage. How far do you need to drive to save that $20,000? Short answer is a LONG WAY!
That's why I will stick to our gasser.
Happy Glamping, Norman & Elna. 2008 Winnebago Adventurer 38J, W24, dozens of small thirsty ponies. Retired after 40 years wrenching on trucks! 2010 Ford Ranger toad with bicycles or KLR 650 in the back. Easy to spot an RVer, they always walk around with a screwdriver or wrench in one hand!