I went from 308 to 320 after an oil change, interesting.
I might be wrong, though, i'm in work so i cant check. Did you drive it before the oil change?
Yeah, did about 30 laps over two circuits, then an oil change and then noticed an improvement in BHP figure.
OK, there we go, you now DO get extra horsies after youve driven it, but not as much as if it's just out of the dealership.