Many traffic warnings issues tell it's much better to brake without pressing the clutch pedal. For instance, we drive a car at 120 km/h and suddenly we have to brake in the shortest distance as possible due to some obstacle on the road. What is better? 1) Should we press the clutch pedal at the same time we are braking? 2) or should we press brake pedal only?. In favour of 1) I would argue: yes, I think it will be better to decouple wheel movement from engine movement. Why? because if we decouple it, the effective inertia the brakes must stop is only the car kinetic energy. If we don't decouple it, we must brake the car inertia in addition to the proper rotating inertia of the whole engine, which is rotating at let's say 3000rpm. In favour of 2) I would argue: yes, I think it will be better to not decouple wheel movement from engine movement. Why? because the engine internal will collaborate to brake the car when we leave it coupled to the wheel shaft and releasing the accelerator pedal. What do you think it is the correct answer? Please give logic reasons. Thanks in advance.