Chevy Bolt's aero is a 'disaster,'

[rmay635703]

Originally Posted by paconassa

0.32 is, indeed, a disaster.

#1 problem with EVs is highway range, so that Cd does not help at all.

With a proper, 21st century, drag coefficient of ~0.20, the Bolt would have a ~30% longer range on highway.

Actually with the intense advances in rr (which seems to be where most focus is by big auto)

The improvement might be more like 50% at the speeds people seem to drive.

[paconassa]

Originally Posted by rmay635703

Actually with the intense advances in rr (which seems to be where most focus is by big auto)

The improvement might be more like 50% at the speeds people seem to drive.

For those speeds you refer to, we need zero EV development, any EV suffices. Who cares about 300km range @ city speeds...?
For long trips at highway speeds, aero is the top range killer

[danwat1234]

Originally Posted by paconassa

0.32 is, indeed, a disaster.

#1 problem with EVs is highway range, so that Cd does not help at all.

With a proper, 21st century, drag coefficient of ~0.20, the Bolt would have a ~30% longer range on highway.

Yet is rated for 110MPGe highway. I don't know if that is estimated manufacture or final EPA.
Doesn't sound too bad but could have been better.

Concerned about almost no buffer in battery in order to get the 238 miles range

[ChewChewTrain]

I know that a lower number is better. But how much lower is how much better in practical, day-to-day terms?

And, what's the theoretical smallest drag number we can expect?

[kurzer]

from 0,32 to 0,26 is like going 90km/h instead of 100 km/h.

[ChewChewTrain]

Ah. Thanks. So the benefits of a slippery car don't shine until you do freeway speeds.

According to the Cummins' MPG research, speeds below 55mph is mostly a rolling resistance game. Speed above 55mph turns into an aerodynamic game.

For those that might have missed my posting, you can read it here:
https://cumminsengines.com/uploads/d...whitepaper.pdf

[paconassa]

For a Nissan Leaf, 0.20 would mean 46% higher range at 120 km/h

[freebeard]

And, what's the theoretical smallest drag number we can expect?

Paging aerohead.

[SlideWRX]

Originally Posted by NeilBlanchard

I wonder if GM has looked at video side mirrors? That could lower the Cd significantly and reduce the frontal area, too. They are using a optional rear view video mirror, so they have the chops.

Video side mirrors are not (yet) legal.

[madodel]

Originally Posted by Vman455

That sounds too good to be true, so I went searching. While some magazines, like Auto Express and Automobile Magazine, reported Cd .24,
Bentley's own press release specifies Cd .34 for the Bentayga.[/url] Doh!

Maybe they confuse the Bentley with the Tesla Model X which does have a CD of 0.24.