Heh, I would actually consider automatic transmission to be the more expressive one, since to me expressive means how easy it is to express something. Analogously e.g. C++ (manual) is more efficient and allows finer control, but makes it harder to express the same thing as in a 'higher level' (automatic) language.

Otherwise, since Assembly provides the most control out of all, would you consider it the most expressive? ;-)

I guess in my head "expressiveness" is some fuzzy combination of what you are able to do plus how easy it is to do those things. I'd consider a calculator that supports real numbers to be more expressive than one which only supports integers, all else being equal.

Maybe this definition is idiosyncratic, though. It's certainly not objective.

I'd agree that "what you are able to do" seems like it's intuitively part of expressiveness, but due to Turing completeness you don't have any situation where language A can compute something that language B can't. So the only difference in capabilities seems to be in how easy it is to compute something, rather than if one is able to do something.