Interesting Aerodynamic Cars (Mike Vetter's ETV, also Avion)

[NeilBlanchard]

The Mercedes EQXX has a Cd of 0.17. It doesn't have rear wheel skirts - but the rear wheel track is a whopping 50mm narrower than the front track. So, a tiny drop, actually.

https://www.youtube.com/watch?v=F0KRisaExyQ

[NeilBlanchard]

The Aptera Delta vehicle has been revealed - Cd is 0.13, I believe?

https://www.youtube.com/watch?v=PQuLuHzR52M

By the way I have a $100 deposit in on the Launch Edition, which is estimated to cost $33,200. 42kWh pack, three 50kW in-wheel motors, 700W total solar cell capacity, upgraded audio. The fly in the ointment is no DCFC - though hopefully this is upgradeable. They estimate ~400 mile range - that means ~10 miles / kWh, which is amazingly good.

[freebeard]

0.17? Imagine what it could do with fender skirts.

It looks like the concept car's retractable box cavity has been reduced to the diffuser.

[The Toecutter]

Originally Posted by freebeard

0.17? Imagine what it could do with fender skirts.

It looks like the concept car's retractable box cavity has been reduced to the diffuser.

I suspect if both front and rear wheels had skirts, Cd value would approach 0.12.

[freebeard]

Fineness ratio? We don' need no stinkin' fineness ratio!

I broke the 1/4-mile world record in this new HYPERCAR!

A one ton car with two tons of downforce at 0MPH?

[Phase]

Originally Posted by freebeard

0.17? Imagine what it could do with fender skirts.

It looks like the concept car's retractable box cavity has been reduced to the diffuser.

They said their engineer team wasn’t allowed to do rear wheel skirts. So that’s why the wheels are big, the tires are flush with the flat hubcaps, the trailing edge is smaller, and wheel arches are small. They claimed in some video that they did such a good job, that wheel skirts wouldn’t have made a diff. They also claimed they have the lowest drag side mirrors ever made too and that it barely even affects their total overall drag

So by guessing from what the engineers said, doing a full fender skirt and removing mirrors would only drop the cd by 0.005

[freebeard]

At 3:44 in the video at Permalink #4125 above they show a rear view mirror on a production car, allegedly lifted from F1, that uses a converging duct to accelerate that mirror's wake.

[aerohead]

Originally Posted by The Toecutter

I suspect if both front and rear wheels had skirts, Cd value would approach 0.12.

I'm guestimating that she'd need 52" of boat tail added, and a 'slower' diffuser along with full skirts to get there.

[aerohead]

Originally Posted by Phase

They said their engineer team wasn’t allowed to do rear wheel skirts. So that’s why the wheels are big, the tires are flush with the flat hubcaps, the trailing edge is smaller, and wheel arches are small. They claimed in some video that they did such a good job, that wheel skirts wouldn’t have made a diff. They also claimed they have the lowest drag side mirrors ever made too and that it barely even affects their total overall drag

So by guessing from what the engineers said, doing a full fender skirt and removing mirrors would only drop the cd by 0.005

Do you have a link to the video?
I'd like to watch that. Thanks!

[Phase]

Can’t remember. I watched too many videos on it lol. But engineering explained just did a video this week on the car. He’s probably the most legit and scientific channel on YouTube.

https://youtu.be/8kY7BGGtDeY