GM did a fairly decent job with their 3800/large sedan/a/t combo. I've long wanted to see one with a 5-speed and a few other modest unobtrusive ecomods.
Edit: Actually starting '96 Camaros could be had with the 3800, m/t or a/t. Old EPA put the m/t at 30 hwy; a/t at 29... not much difference but the moderately alert ecodriver could do much more with the m/t. An honest 30 mpg with that sort of power is pretty good IMHO.
I've long maintained that GM ENGINEERING knows what it takes to extract maximum fe. They are on the leading edge of much tech back in their R&D Department.
Too bad they don't have more influence on what gets produced. Once again, I point my bony finger at the idiots in the Marketing Department.