How does less than zero weight oil perform on the street?
One of our Brock's Performance customers does road race track days, drag races, and street rides daily with his 2001 GSX-R1000. He has over 12K miles using less than 0 exclusively after his first oil change. We use it in all of our stock engines up to 200 RWHP.
If you are worried, try the 0W-20. The only adverse effect we have ever seen with the less than zero is a bit more valve train noise since the <<0 is so thin. This is usually only an issue if the engine has a slightly loose valve to begin with, or excessive miles.