I found this while doing some research on oils. It's not completely scientific, but it's interesting for a couple reasons. The engine was spinning a propeller, and rpm differences show as power increase or decrease. Opti-2 was not used in this test, however the only 100-1 test showed piston scuffing, whereas none showed in any other test. I'd look at that as a headsup. No extra power, but extra wear. The most power was @ the beginning of a test @ 32-1
If nothing else, that was a real tough test, hours running at full throttle. Nascar engines only run 3 hours and are torn down and rebuilt or sold. This sucker endured quite a beating.