Where do you guys normally shift your cars? Seems if I let the tranny shift itself, it shifts at only 4000 to 4500 (MAX) rpm. Is this a little too low? I have rarely seen the red LEDs on my factory tach (which begins at just over 5000, right?), and I have NEVER hit the rev-limiter. Do you think I would have much to gain by holding the car in gear until I see a red LED?