Nissan Leaf Alternative to Side Mirror Delete

[Rokeby]

Of late, I've seen a number of very late model cars with what looks like a
wedge moulded into the headlight lens cover. I've seen these on various
Honda models, notably the Fit. The wedge is about the size of a box of
matches and is aligned with its blunt edge facing forward. I've wondered if it
could be aero related.

While looking through some Nissan Leaf info I found these tidbits:

... The design appears successful as the upright stance affords a spacious
interior with plenty of room for at least four people. Aerodynamics were not
overlooked though as the LEAF has a smooth underbody, a unique headlight
design that manages airflow around the front of the vehicle and a smooth
front end with a unique logo that hides the charging port... Source

... The headlights are more compelling, bulging out from the fenders more
than some concepts displayed on the auto show circuit every year.
Predictably, they serve a functional purpose. When Nissan was testing the
Leaf, they noticed a fair amount of wind noise coming off the side mirrors.
And with any EV, exterior noise is amplified due to the lack of racket
emanating from under-hood. So the lights were redesigned to split the air
leading towards the mirrors, eliminating buffeting and drawing a clear line
through the atmosphere... Source

Here are some shots of the Leaf's headlights (Click to enlarge):










Good golly, Miss Molly!

Severely fugly, but they are an aero feature...
not some EMF-hyped autonomous blob squeezing
its way out of the engine bay.

It would be rewarding to do some tuft testing on a
Leaf to see what's happening.

Absent that, is this something that might add a few points to Cd and MPGs?
I guess you have to do some tuft testing to trace the airflow around a
vehicle's side mirrors forward to the headlight area.
Then would come the question of how the DIY version should be shaped...
wouldn't it be nice if it were some portion of a cast off water/soda bottle!
For tuft testing purposes, shapes could be temporarily held in place with just
about any kind of tape.

Any thoughts/comments... thumbs up thumbs down ??

[cfg83]

Rokeby -

The design intent was to reduce wind noise, but we like to correlate wind noise to overall improved aerodynamics. I am going to claim it is a wash (of less noisy air) because it is mitigating a perceived problem that is actually masked by normal gassers with noisy ICEs.

If they offered a camera-side-mirror option, they could ditch the external side-view mirrors and the headlight lens bumps.

But I am waiting for aerohead to chime in.

CarloSW2

[cfg83]

Rokeby -

I don't like the design of the Leaf either, but this angle hides a lot of warts :



It actually looks "nice" to me from this angle. Maybe it's time for a trip to the optometrist, .

CarloSW2

[basjoos]

One thing I don't like about the Leaf's headlight placement is that they are getting too close to the driver's line of sight. This would make driving in fog more hazardous. The closer and more parallel your line of sight is to the headlight's beam, the less you can see since you are looking down a line of light scattered by the fog. Ideally the headlights should be positioned as far from your line of sight as it is possible to mount them on your vehicle. That's why fog lights are usually mounted on or under the front bumper.

[orange4boy]

My bet is that it's all styling.

The explanation of a "splitter" sounds like hokum to me.

Predictably, they serve a functional purpose. When Nissan was testing the
Leaf, they noticed a fair amount of wind noise coming off the side mirrors.
And with any EV, exterior noise is amplified due to the lack of racket
emanating from under-hood. So the lights were redesigned to split the air
leading towards the mirrors, eliminating buffeting and drawing a clear line
through the atmosphere...

"Predictably"? Uh, whatever.

I think it's "marketing" A way to give people a reason to like the bulgy fisheye look which seems to go with the fishmouth bumper.

They should have called it the Nissan Catfish.

I do wish it every success. If I had the cash and the Aptera wasn't coming (please) I'd buy one.

I noticed a big difference in a-pillar wind noise when I installed a 6" windshield wiper / cowl cover on the Prius. I'm guessing that Turbulent air was bleeding off the corner of the cowl and separating as it went over the pillar. The cover smoothed all that out. The leaf has a very different front that looks like it has minimal a-pillar separation.

[robchalmers]

european pedestrian crash test / headlight minimum height law. similair thing in Japan.

[The Toecutter]

I've seen two claims for the Nissan Leaf's drag coefficient:

0.28:

Nissan Leaf offers much more than zero-emission driving - egmCarTech

0.29:

"Nissan Leaf EV: First drive" by Maynard's Garage

Do a search and these two figures are repeated around the internet.

Fairly unimpressive, considering the average new car sold today is about a 0.29-0.30.

They need to roll out a sub 0.20 Cd car with their next model line, which would dramatically improve range without adding much to the cost. Trying to go after small gains such as changing the shape of the headlights, when much larger gains can be found by modifying the car's rear end, just doesn't make much sense...

[robchalmers]

But trying to park a subcompact with a 3-4ft boat tail maybe a little difficult! even if you do get more trunk space!

[Varn]

I used to be active in recumbent bike racing. Splitter technology does work. It can give another mph or two at 40 in a coast down. I think it is similar to vortex generators. Giving up a little to gain more.

I would be easy to try making a splitter on about any car.

[cfg83]

Varn -

So you're saying I could put a little "ridge" or "fin" in front of my side view mirror and split the air in advance of reaching the mirror? I guess I would verify this with tuft tests and/or listening for reduced buffeting from the wind.

CarloSW2