GM Volt Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
1,314 Posts
Discussion Starter #1

·
Registered
Joined
·
200 Posts
Drag is a high-speed thing...

How much this affects your electric range would depend largely on how you USE the electric range. If you're driving around urban and dense suburban areas at 30-40 mph with lots of start/stop, small improvements in drag aren't going to drastically increase the range. If you spend a lot of time in the 50-70 range without having to stop much, drag reduction makes a much bigger difference. I think this will improve the car's gasoline range more than its electric range on most trips, but for people who travel at highway speeds on electric power it will boost their electric range as well.
 

·
Registered
Joined
·
251 Posts
This could have been a 7 mile improvement from the initial design needed to bring AER up to the 40 mile goal. GM is always going to present the best possible case. He still referred to Volt as 40 mile AER.
 

·
Registered
Joined
·
812 Posts
What this means is putting the batteries into the concept volt frame would give you 33 miles. Their 40 mile estimate was always based on the assumption of a more aerodynamic frame.
 

·
Registered
Joined
·
1,314 Posts
Discussion Starter #5
What this means is putting the batteries into the concept volt frame would give you 33 miles. Their 40 mile estimate was always based on the assumption of a more aerodynamic frame.
That is what I've always read. From the beginning, it was always the target of 40 miles, assuming the normal driving profile that they discussed. Nowhere was it stated to be 33 or 34 miles as the target range. So this news would have me believe that the improvements are additional, and that it would help the Volt push over the target range of 40, pushing perhaps by 6 or 7 more miles, at least from the sequence of news or updates that I was tracking. If not, what is the purpose of the latest news about improving the aerodynamic efficiency?

Nonetheless, I'd be happy that it would achieve 40 miles for the assumed driving profile and conditions.
 

·
Registered
Joined
·
1,916 Posts
The more interesting part of today's article is that they reduced the drag coefficient by 120 points. I assume this corresponds to a reduction in Cd by .120. If I remember correctly, GM had mentioned at one point that the concepts Cd was .36 or .38. This would mean the production Volt will have .24 or .26 Cd.

I believe Tom ended up using .25 for his models.

Since they were talking in context of improvements from the concept, I'm sure the additional 6-7 miles of AER is in this same context. GM stated the concept would not get 40 miles, so I agree with Tom's assessment.
 

·
Registered
Joined
·
1,314 Posts
Discussion Starter #7
The more interesting part of today's article is that they reduced the drag coefficient by 120 points. I assume this corresponds to a reduction in Cd by .120. If I remember correctly, GM had mentioned at one point that the concepts Cd was .36 or .38. This would mean the production Volt will have .24 or .26 Cd.

I believe Tom ended up using .25 for his models.

Since they were talking in context of improvements from the concept, I'm sure the additional 6-7 miles of AER is in this same context. GM stated the concept would not get 40 miles, so I agree with Tom's assessment.

The news would have been truly very clear if they have stated that these new improvements are needed in order to achieve the target range of 40 miles per charge under normal driving profile, rather than reporting 6-7 miles of extending the range.

I wonder why they didn't report it that way.
 

·
Registered
Joined
·
1,916 Posts
Why is everybody so critical? The context of the presentation was about the design changes they made, why they made them, and what affects those changes had. His statements were perfectly reasonable in the context of his presentation. They just cannot present all of the information everybody wants, all of the time.
 

·
Registered
Joined
·
35 Posts
They didn't report it because it's a fluff piece by a guy who doesn't know much about the subject would be my guess
They didn't report it because they probably didn't know. But as of this morning we do know. It's still going to be just 40 miles, but without this extended range we wouldn't be at 40 miles.
 

·
Registered
Joined
·
108 Posts
The type of driving that would most benefit from an aerodynamic change exactly fits my driving style.

Each morning, I drive 1.5 miles on city streets to get to the expressway. I then drive 18 miles on exxpressways/freeways at 50-70 mph, then I get off and drive .9 miles to work in a commercial district.

Sounds like these improvements are perfect for me. Go Volt!
 
1 - 11 of 11 Posts
Top