Any good vehicles from the 1960's or 1980's that are good on gas?

I'm wanting a vehicle that is good on gas and that is large size. I have a strong love for GM, Fords, Chevrolet made in that era. I'm looking for a large size car that is good on gas.

Obviosuly only 4-cyclinder cars and nowhere near as good mpg as newer cars

If you consider 15 mpg good, you can find some mid sized boats with small engines and no performance…

I can just about guarantee you won't find any. The big cars of those years were All gas hogs. The engines were much less efficient than today's are and moving that weight and frontal area required fuel.

The best you will find of those years is a 1989 Ford Crown Victoria. 17 city 24 highway when it was new. Don't expect to get that on a used one.

My first new car as 1986 Dodge Colt, which was really a Mitsubishi. It got 36 MPG all the time. If I did long trip on the highway, it would get 45. But if you wrecked it, you died.

Your priorities are messed up. Old cars are expensive to run. If fuel economy and cost is a concern don't buy an old car. I'd actually be more concerned about maintenance costs. Cars from the 60s are beautifully styled, but you'd be lucky to get 20 mpg out of a six cylinder engine, let alone a V8 engine found in a large car. Domestics from the 80s are absolutely horrible in build quality and engine power output. Stay away.