Well, a read of the owner's manual would be a good idea .
The CVT has three modes:
Normal CVT mode (D)
Sport Mode (SD)
And Steptronic (Shifter to the right and toward the dash to downshift, towards the back to up shift, the starting point for this is the SD mode, it changes to manual mode when you shift.)
First of all, you should avoid Sport Mode during the run-in (break-in) period as you may over-rev the 4500 RPM limit.
After the run-in period, yes indeed, you can shift between modes while driving. I have often shifted from normal mode to SD, then downshifted to pull out and overtake a car, then shifted back to normal mode to cruise. I am very pleased with the CVT, although I need the CD33 fix to prevent the surge at a stop.
The SD mode, as you noticed, generally rev's a little higher, and also seems to have more dynamic braking (using the engine to slow the car). It is quite good for the twisties or maneuvering in traffic.
The CVT also uses an adaptive technology so the car "learns" your driving preferences; All in all, a nice little device.
Oh, and Welcome to MINI2.
