Why Can a Dual-Powered Super Capacitor/Ultra Capacitor Electric Car Save Fuel?

https://www.kamcappower.com/super-capacitor-ultra-capacitor-electric-car-can-save-fuel.html

The biggest advantage of dual power super capacitor electric car is to give full play to super capacitor in the case of low speed and heavy load, the energy is not lost; in the case of deceleration, downhill, and braking, the energy can be recovered.