The shift light is fuckall to do with the optimum. as said a thousand times it's merely a warning that the limiter is fast approaching.
Any half decent driver should be able to feel when the power is beginning to drop off and learn when to change to drop you to roughly where your peak torque is.
Any half decent driver should be able to feel when the power is beginning to drop off and learn when to change to drop you to roughly where your peak torque is.