Swamp is correct. The M5 does not need to be shifted at red line in the higher gears as clearly indicated in the graph. This is also true for the 1M. I came to the same conclusion with a similar analysis previously.
To me, this is also an indication that the gear ratios on the M5 were not optimized for best overall acceleration (maybe a compromise for MPG and/or comfort
). 1st, 2nd and 3rd are too far from each other while 4th, 5th, and 6th are too close. I would keep 7th with a taller gear for MPG. Choosing gear ratios that would allow the force line of every gear to touch the force line of the next higher gear without crossing would yield better acceleration over the entire range.
My hope is that the F8X M3/M4 DCT ratios are better optimized to take full advantage of the new engine.