Small block mileage

Of all the 2000’s and older from Chevette to Crown Vic never saw much difference in all of them, I get 15-16 mpg in town some a few mpg less and some a few more.

My Dodge Avenger is probably the best I’ve driven 22-23 mpg in town.

I wouldn’t worry about it.
Similar performance is gonna eat about the same amount of gas no matter the engine size.

Is it a summer toy that get only a few thousand miles on a year? If so a couple of mpg ain’t gonna make that much $$$ difference anyways.

Plus a car will take a certain amount of hp to move it down the road which will take basically a certain amount of fuel in a narrow range, different engines might be slightly more efficient than others doing it.