Over at Salon.com, David Sirota asks if it is "ethical" to drive a manual transmission. The reason for his question is recent news that more people are choosing manuals, and also, that automatics are now sometimes equal to or better than manuals in fuel economy.
I find it odd that he only considers fuel economy in his question.
A more careful ethicist would also consider the resources going into the transmission. For example, a manual will over its lifetime consume one or two clutches. An automatic (unless it is one of those rare CVTs) will consume several changes of automatic transmission fluid, a.k.a. oil.
Also, consider that automatics usually cost about $1000 more than a manual. Why is that? Simply, omplexity. The automatic has more parts, including electronic controls. More parts means more manufacturing footprint to make it.
It seems to me that manuals are more "ethical" than automatics until such time as their fuel economy gains can overcome the manuals advantage in simplicity.