Of course, there are other cold factors to consider (with solutions).
Problem: Cold Starts lead to longer Open Loop conditions
Solution: Engine Block Heater
Problem: Vehicle oils become thicker as the temperture drops
Solution: Transmission fluid is often run through the radiator, so an EBH would heat up the rad. For the engine oil, the EBH is a bit more indirect, but seems to keep things warmer than nothing at all.
Problem: Some cars like hot intake air to lean-out the mix for better FE
Solution: HAI, and modified aerodyamic additions to keep the cold out of the engine bay or hot air source. Common treatments - grille block, sealing the hood, and/or a diverter/undertray.
Problem: Tire pressure drops with temperature
Solution: Check it more often.
Problem: Adverse road conditions: Snow/Ice/Rain
Solution: Time. I got nothing for this one, really. The extra friction to push away the precip. reduces FE. Decent tires could help.
We had a couple of cool days and nights here and I already see the cold temp indicator staying on TOO LONG - gonna wrap more of my exhost with aluminum foil to get the cat warmer - maybe I should think about enclosing the engine in insulation too!
Hey maybe they will figure out that the E10 doesn't work well in cold climates and get rid of it for the winter . . . wouldn't that be cool!
Not a chance since ethanol is the magic bullet that will save us from our addiction to foreign oil.
As far as additives go, I don't think there's anything that would convert the ethanol into a more efficiently-combusting material (I should say antyhing inexpensive). Aside from buying it in bulk, separating it somehow through refining, distilling or every else I forgot from Organic Chemistry, then I'm at a loss.
Since MTBE is a cancer-causing agent, I would definitely give up some conveniences to not use it. The whole ethanol debate could go on for decades -- I prefer Bio-Diesel, but limited access to it currently in the area, and no Diesel engine kinda rules that out - for now