I just put it into D+ and let it sail. Or Dauto, then its D+ with automatic change to D if there is a car ahead or speed must be reduced. Anyway, when you press a brake pedal, the brakes are not used, its engine slowing the car by returning its kinetic energy back to battery. Most important rule is to try to do less intensive slow down over longer distance, i.e. energy back at 20% over 30 seconds is more efficient than energy back at 60% over 10 seconds. D mode gives -20% of braking by using motor as generator when gas pedal is not pressed. D- for me is only good for going down the long hill, if you do not like to keep brake pedal a bit pressed and do not use autopilot. D-- is brake and gas in one pedal, I prefer to use 2 pedals. The alternative way to achieve D+ sailing in D mode is to keep gas pedal a bit pressed, then it sails, if you press the gas exactly to the point where energy to/from battery is shown as 0%. This is personal taste, I find it more convenient to press brake pedal if slow down is needed rather that keeping gas pedal a bit pressed in order to keep the car sailing. The end result is the same, you see it in % of energy taken or returned to the battery, and the economy driving rule is to slow down equally over remaining distance, and also accelerate slower. Sailing, instead of slowing then accelerating, is more efficient, that is why I use D+.
Personally, I find that ECO mode is best for me. In that mode the accelerator pedal has a good intermediate "stop point" and it needs to be pushed a bit harder to accelerate above the "normal" level, and that reminds me not to press it more just accidentally. After using a petrol car, if you press gas to the bottom in Comfort mode, the EQC400 becomes a rocket and the tempo of acceleration may scare passengers, if they are unprepared for such a huge 300kW traction power. As my wife says, on this car you cannot press gas to the bottom when driving home after large dinner. Great car.
