It is my understanding that the Drive Mode Selector is not so much pre-programmed maps used to retard power, but actually a control system to manage the stepper motors that operate the secondary throttle valves. For the sake of those that are not familiar, the modes are as follows:
A - you get the throttle your right wrist asks for
B - secondary throttle valves don't open as wide as the cable controlled throttle valves until you hit wide open throttle
C - secondary throttles never open as wide as the cable controlled ones
That being said, it would stand to reason that 'B' and 'C' modes would offer better economy, being that the amount of fuel being delivered is restricted. However, when you factor in the myriad variables that exist in the real world riding conditions that we all experience, I would bet that the difference would be negligible. Just as careful riding in 'A' can yield impressive mileage numbers, beating the hell out of the bike in 'B' and 'C' mode can leave some scratching their heads at the lack of decent miles per gallon.
TL;DR - MPG are going to depend much more on riding style and environmental variables than the chosen power mode of the bike.
Just my :2cents: - I could be way off base here, so take my assumptions as simply that.
