the yellow min manoeuvre lines on the speed tape are just that for whatever configuration you are in. On a classic 400 in cruise at or near optimum levels for weight, that yellow line indicates min drag or holding speed I think and is the engine out drift down speed. If you are flying an 800 at optimum levels then add 15 knots to the yellow line to find min drag drift down or holding speeds. Airmanship consids, why fly at a speed below min drag in cruise? take a hold or vectors to lose time is better option