S!
OK, studied the graph. Texts are a bit hard to read but anyway. Rotating it clockwise makes it easier BTW
OK, rotate pic 90deg and you see what I mean. Left side (Y-axis) is speed in km/h and coolant temp in Celcius. Top curve is for DB605A(marked with a *), lower curve DB601E(marked with a triangle). Lowest curve is the temperature curve and for both engines pretty much the same. X-axis is the opening of the cooling flaps in millimeters, 0-400mm.
IT seems the flaps were open 50mm and 81mm respectively. The note says something like: Just for comparison for DB601. DB605 is not usable because of the non-standard cooler and the cruising altitude, absolute values, see VB 109 18 L42 (must be a technical report) The harder to read note says something like: Not credited. automatic values in H=2050m