This is a big RV with a massive, 6.2 diesel motor. Unlike most Class C's, it doesn't have a van-cab; it looks more like a Class A, built on a truck chassis. Popular in the mid-'80s, this RV is a great one and can still be found. And if it's in good tune, it should deliver gas mileage between good and great.
Fourwinds' Class C, even with a massive V-10 motor, is capable of cracking the 11-mpg barrier. Part of its good mileage (in spite of 10 cylinders) is due in part to a more modern generator and in part to its somewhat diminutive size, at 24 feet.
The Chinook is a 25-foot-long Class C built around Ford's popular pickup-truck motor/chassis package: the Powerstroke Diesel. Ford is known for reliability, but there are exceptions. Some model years had some nagging problems, but most are reliable, and you can expect good gas mileage.
Built on a Sprinter Diesel chassis, Winnebago, the most popular motor-home manufacturer, has an entry in the Class C good mileage club: the Vista. This one might even get you over 20 mpg.
