It doesn't take 20 miles for this function to be activated.

On a new car there might be the eprception of something like this due to the normal adaptation process for the shifting to get completed.

The "adaptive shift program", the thing that decides whether you are driving sporty or driving economically, does its program choice in thousandths of a second.

The idea behind getting rid of the switch used on earlier 850's, s-v-c70's, and the -2000 s-v40's is to do away with a situation where you driving conservatively and you come upon say a farm machine driving in the hroad and you need to pass it quickly but not superfast. In 'E' mode the trans would likely not downshift unless you went hard to the floor, whereas if you depressed the 'S' button you would get better acceleration when the more sensitive 'S' program gives you a part-throttle downshift.

The adaptive shift program will detect that you moved accelerator pedal aggressively and automatically goes to its 'S' mode and you get the part-throttle downshift w/o you having to plan ahead.