Drag climb vs cruise.
According to a presentation made by Boeing a 737-800 cruising at 35,000 feet0.74 mach (close to min drag speed) has a total drag of 8,750 pounds.
In the cruise again the total drag at mach 0.8 is the same as at 0.67 (9,500 pounds).
My question is this....how significant would the drag increase be in the climb towards this cruise altitude with a low (say 500 feet / min) climb rate at a speed of 0.67 mach.
I assume that the increase in lift generates more induced drag ...but does anyone have any rough ideas how much more than the 9,500 pounds figure?