[jameshart]

The control scheme has nothing to do with the efficiency of the car. Whether one pedal or two, it’s going to use the same power for the same acceleration/cruise/deceleration profile.

Unless you’re concerned about the energy usage in your ankle when maintaining pressure on the gas with your foot?

[k8sToGo]

It has to do with that your feet or legs are not super accurate machines that can keep the pedal at 0 regen and 0 acceleration for long enough time.

[jameshart]

Controlling the car’s speed is the driver’s primary job. One pedal or two you need to use your right foot to maintain the speed you want.

Coasting with no acceleration or deceleration except that provided by rolling resistance and the road gradient is so unlikely to be the exact acceleration you actually want - there’s no particular value in privileging ‘zero motor power’ as needing to be an easy state to achieve.

[AnthonyMouse]

There is a decent sized gap between 0 acceleration and 0 regen equal to the amount of energy required for the vehicle to maintain speed against rolling resistance and air resistance. Anywhere inside that gap, you're not using regenerative braking at all, you're just decelerating from not supplying enough power to maintain speed.

[k8sToGo]

That is not the type of cruising this is referring to. It is the wrong name, to be fair. It really is just letting the car roll.

[AnthonyMouse]

"Just letting the car roll" results in deceleration, but at a rate chosen by physics rather than you. If deceleration is not what you want, you have to continuously apply power. If it is what you want, it's still almost never going to be at the rate you want, so you still either have to apply some power or apply some braking. In the former case, you're pressing down on the pedal enough that no regenerative braking is happening. In the latter case, regenerative braking is obviously more efficient than friction braking, because the latter has 100% losses to heat.