Performance improvements with engine oil are mostly due to viscosity, so thinner is better. That should spin your head when one marketer says their "racing oil" is so much better than another. (Within each SAE grade is a range of allowable viscosity, so they formulated to the thin end.) As OEMs and engine builders learn how to make round things perfectly round and flat things perfectly flat, using a lower viscosity oil will be more and more normal- witness the SAE 5W-20 factory fill oil in the new HEMI engine.
Something that is called 0W-0 (although there is no official viscosity grade lower than SAE 20) would be great until the oil warmed up significantly, which takes longer than a drag race. NASCAR restrictor plate qualifying oils are this thin; good for two laps, then shut it down.
Protection of non-hydrodynamic lubricated parts (valvetrain, piston pins, to some degree skirts and rings) will still be via additives. Anti-wear additives, friction modifiers, balanced with the right amount of detergents. Adding too much of one screws you up, since these additives compete for metal surface sites. While an ashless friction modifier has it's place, too much of it will keep anti-wear additives from doing it's job. A fully formulated oil is always safer than adding to an oil.
I've formulated oils like this. My technology consulting company recently had an "interesting" business experience which leads to offering this oil to the public.
http://cgi.ebay.com/ebaymotors/ws/e...RK:MESE:IT&viewitem=&item=250100337664&rd=1,1 It's an SAE 0W-20 (although the performance would be better than "0W", there is no official category lower than "0W.")
