[rootusrootus]

Regenerative braking is always, always less efficient than just not spending the energy in the first place to speed up.

And there are currently more fossil fuel cars on the road with regenerative braking than there are EVs ;-)

[_ph_]

To use 60% less fuel, the car needs to havee appropriately less mass, so you are talking about 700kg for a 5 seated car with passengers. If you are talking about fossil fuel cars with regenerative breaking, you are talking about hybrids, which use their electric part for that, but their breaking power is limited compare to pure EVs by the electric engine power and the charging limits of the smaller battery.