The problem with internally geared chain drives are that the chains usually still have oil on them.
So a few months ago I cleaned the oil off my chain and haven't put any more on since. I've not been able to detect any loss of efficiency or any increased wear.
I think most of the problems with unoiled and/or worn chains have to do with derailleur shifting anyway. It's hard to imagine why a chain would need oil just to drive a single cog. I guess it's possible there might be some friction between the chain plates, but I would be very surprised if there weren't more friction between my thighs and the saddle.
Last edited by makeinu; 01-27-08 at 06:45 PM.