Originally Posted by AlexK

Not really. For example, you won't lose the warranty if you always drive in D/S (or M/S, depending on the model) transmission mode, even though it changes throttle programming to be more responsive (same goes for BMW models with Dynamic Driving Control). I believe it has more to do with car's manufacturers desperately trying to improve the numbers on EPA (for USA models) sticker - EPA tests cars only in their "default" settings (with automatic transmission in "D" mode, or with DDC in its default position), that's why the "default" settings must be as fuel-efficient (and with least amount of emissions) as possible, regardless of any other condition.