The Cd has more of an effect on range at the higher speeds because of the square factor of the velocity; At 35 mph and below, it is almost negligible; even at 50 mph it is fairly minor. Also, a Cd of .28, which is what the Leaf has, is very good for a street car; Tesla's Cd is only .04 better, very minor. However, one improvement, that is estimated to improve range on any car by about 3% at speeds, is to replace the sideview mirrors with cameras.NeilBlanchard wrote:Having a low Cd is the best way to extend the range for any given battery pack capacity. So, having a lower Cd means a longer range with an smaller pack; which means a lower price.
So, I hope they go in the direction of the Renault Eolab concept; which I think looks even better than the Sway concept.
Want to improve range? reduce the weight like BMW has on the i3 which weighs about 2,700 lbs which is about 500 lbs less than the Leaf. Another major factor, other than a higher battery energy density, is friction and the major device in friction is the tires which Nissan has already addressed with low rolling resistance tires. Some additional work can be done in the area of friction by eliminating the differential gearing and and the reduction gears and installing two smaller computer controlled and synchronized drive motors instead. Additionally lower friction lubricants can be used on all bearing surfaces.
There is also work proceeding to increase the efficiency and reduce the weight of the electronic devices: The first one that comes to my mind is to replace the Leaf's lead battery with a smaller, lighter Lithium battery. One reads a lot of about Lab work to reduce the heat losses, the size and weight of the Motor Control Unit, DC to Dc Inverter and on-board AC Charger by moving over to graphene devices. Hopefully one day this will be in mass production.
BTW, the AC Charger doesn't need to be on board the car. If one charges at home and uses quick charging stations for distance travels, you never use the AC Charger. You can hang it on the wall at home or use a small DC quick charger at home. Think about it. That's what racers do...saves weight and simplifies the design. And, if you just need to feel psychologically safe, you can build up a small AC trickle charger with a rectifier for comfort.