In my last post, I touched on the car's ECO mode and driving and braking modes. These features are not well described, so I'll take a crack at it here.
The ECO mode extends battery life by reducing the power profile. The Leaf has a lot of power - it accelerates unlike any other car in its class. The “gas” pedal though isn’t sending gas to the motor, it’s sending electricity. Think of the gas pedal as a dimmer switch. Most dimmers are linear, as is the Leaf’s accelerator. Push it 10% more, and you get 10% more power. If you put the car in ECO mode, it readjusts that curve so that you get much less power initially.
When the traffic light turns green and you (out of habit) press the accelerator half way, it uses quite a bit of power. But since the Leaf is so quick, most don't require all that power. ECO mode turns the acceleration profile into a normal gas-like car. The clever thing though is that if you floor it, you still get full power, so you have it all when you need it. It’s a nice way of extending battery life without much pain.
Braking mode is also clever. Like a hybrid, the car can use the vehicle’s motion to run a generator and charge the batteries. This process slows the car. In normal drive mode, this braking power works in tandem with the brakes. That is stepping on the brakes activates both the generator and the brakes - the car will brake normally, but if you brake slowly the generators will get more juice.
Putting the vehicle in Braking mode means the generator braking is activated by not accelerating. In other words, there is no coasting because the regeneration friction is actively engaged. It may not sound particularly useful, but it is. In city driving, one is generally either accelerating or braking. In Braking mode, there is less need to use the brakes and more recharging. Once I get onto the highway, where coasting is more useful, I switch back to Drive mode.
As I stated in my last post, the Leaf needs some improvements to its user interface. For some reason the ECO mode is a button on the steering wheel and brake mode requires moving the gear shift into drive twice. ECO mode has memory, it’s on until turned off. Braking mode requires active selection each time.
All in all, the Leaf is the favorite car to drive in hour household. The other vehicles are an Acura and Infiniti. We love the leaf and are looking forward to seeing Nissan and others continue to improve the all electric technology.