WIRED in depth look (photos) at Nissan Leaf. Also: we'll be able to "coast" a Leaf

[MetroMPG]

WIRED just posted the closest look I've seen so far at the Nissan Leaf EV. Mostly it's a photo piece - they're still only giving road tests in the "mules" based on the Versa.

But I learned a few things from the photos, and asked the author a question that will be on the minds of anyone who wants to know something important about eco-driving this particular EV.

Worth Digging, if you're a digger: Nissan's Leaf Ushers In the Electric Era

Nissan’s Leaf Ushers In the Electric Era



Here's the photo that caught my attention:



See the regen / power indicator at the top of the instrument display?

Looking at that, I'm most interested in the accelerator's "zero point" - the threshold between regen and power. Because if you're a serious eco-driver you want to be able to truly coast at times, and intentionally avoid using regen.

Why? Because bleeding speed by coasting using no energy is more efficient than using regen and converting kinetic energy back into the pack (due to conversion losses, and the shortened distance of regen).

I asked the WIRED writer if he had any details on that. He checked with someone who knew, and the answer came back that the accelerator is similar to the Prius: there's a "neutral" zone where power flow is zero.

"It will take some practice, but you can coast."

---

The writer also asked about the car's drag coefficient:

Nissan wouldn’t disclose the drag coefficient of the Leaf, but said it is “competitive with similar cars.” Whenever an automaker says that, they’re usually referring to the Toyota Prius (Cd 0.25) without actually saying Toyota Prius.

Full article: Nissan’s Leaf Ushers In the Electric Era | Autopia | Wired.com

[Daox]

Good article.

I have to highly doubt that the Cd is that close to the Prius. I'm guessing high .20s. The current Versa is .31. I'm sure they can lower that (no exhaust so nearly flat underbody), but I'd be very impressed if it was down to .25.

[JasonG]

There should be a "regen kill switch" for in neutral type coasting.
Maybe on the steering wheel (no shifter right?)

[Rokeby]

Originally Posted by Daox

I have to highly doubt that the Cd is that close to the Prius. I'm guessing
high .20s. The current Versa is .31. I'm sure they can lower that (no
exhaust so nearly flat underbody), but I'd be very impressed if it was down
to .25.

I can see the front end treatment being Prius-like aero-wise. But It's hard to
see the rear end being that clean:

I keep wondering if this is a red herring with the true shape being held back
for the real car, not what the current test cars are wearing.

Originally Posted by JasonG

There should be a "regen kill switch" for in neutral type coasting.
Maybe on the steering wheel (no shifter right?)

On the Prius, the "no regen, no power" condition, usually called "no arrows
glide," is accessed by small, really small adjustments of the gas pedal. It
takes a little while to retrain you right foot, but after a short while you get
used to it. No extra switches, both hands on the wheel.

[roflwaffle]

I've seen .28 as a Cd figure, which seems reasonable, especially since the Leaf has no airflow thorugh the engine compartment AFAIK.

[NeilBlanchard]

I'm curious to find out if the Leaf has a supercapacitor onboard, and/or if it uses GPS info and elevation info to make "smarter" use of regenerative braking?

[MetroMPG]

Originally Posted by Daox

I'd be very impressed if it was down to .25.

No ICE cooling system, and a completely flat undertray knocks a lot off any car's Cd.

EV1 belly: (from http://ecomodder.com/forum/showthrea...-56k-5598.html)