How can it tighten up the steering? Honestly curious how a button can change steering response.
Pushing these buttons can change the suspension settings on some cars as well. My wife's Fusion absolutely feels like the suspension tightens up when in Sport mode but in this vehicle, there's no indication that sport does anything beyond increasing the throttle level (when I switch from D to S and do not move the throttle pedal position, it will increase 200-300 rpm) and transmission shift points. Those are the only two (major) adjustments that I'm aware of it.
Reason I think it does change the suspension is we've driven on a particular road that has dips and small hills ("humps" ?) and in normal mode, it kind of floats up and down as you go through these. I've had it in sport mode over the same parts and after cresting a hump, instead of floating like a boat, it pulls down very quickly. You will feel it in your stomach, it's so strong.