Campervans What Kind Of Highway Fuel Economy Can Class B RVs Achieve (e.g. Campervans)?

What kind of highway fuel economy can Class B RVs achieve (e.g. campervans)? - campervans

If a person drives at 55 mph or less constant to achieve the kind of fuel these vehicles?

I know that models and sizes, and the fuel consumption per May, but I'm stage. I'm more interested in older models (80s & 90s), but appreciated all the information. Although only one example of a model would be useful (perhaps your personal experience with one).

Thank you!