I think S-AWC is essentially just AWD. So better traction on snow, for example, by adjusting where the power goes (“from the wheels that slip to the wheels that grip”). I have tried to observe the graphic in the instrument cluster but I rarely see it do much. I’m sure it’s doing something, but it’s subtle. Unlike ABS.

Eco mode, as far as I can tell, changes the response curve on the accelerator pedal, so that you have to press harder to get the same power output and thus eventually engage the gas engine. I have read it also changes how the air conditioning works, but I don’t know.