Are there any old cars that are fuel efficient?

When I say old, I don’t mean something built a few years ago. I mean cars that were built in the 1950’s or 1960’s. Realizing, of course, they weren’t as efficient as today’s cars, and I’m pretty sure that in the 1950’s there weren’t any cars that got 36 miles per gallon. What I do mean is, were there any cars that got 20 miles per gallon or so?
If there are any cars like that, what are they?