Comments on: Chevy Volt Vehicle Line Engineer on the Reduced Gas Storage Capacity

By: DVanditmars

DVanditmars — Sun, 20 Apr 2008 00:12:00 +0000

Has anyone that does not like the new range calculated what their current vehicle’s range is, I did.
FuelTank: 15.9 gallons
Average MPG: 22
Range = MPG * FuelTank = 348 miles
Now this assumes a full tank at the start of the trip and ending the trip running on fumes.
Thus for me 400 miles is more than enough based on what I am driving now, (until late 2010 that is).

By: BillR

BillR — Fri, 18 Apr 2008 10:04:59 +0000

#126 doggydogworld

Thank you for your interest in the cross-country driving scenario.

Since writing that, I have seen more data, and I agree with your assessment that the engine will probably operate at different speeds. One reason that leads me to this conclusion is that the regen braking will provide AC power back to the system at variable frequency, so the power electronics should accept a variable frequency from the generator.

I do believe that the ICE will still recharge the batteries while in operation, and may shutdown at other times. See the attached link for GM curves on planned operation.

http://www.motortrend.com/features/auto_news/2008/112_0804_chevrolet_volt_update/photo_03.html

It will be interesting to see final performance numbers for the Volt under ICE operation.

By: far-soarer

far-soarer — Thu, 17 Apr 2008 18:04:44 +0000

I am a dreamer I know, but I think GM is out there way in the future with this small gas tank business. I believe their thinking is “What do we need gas for?”
GM will continue to develop the battery pack for increased range and I believe they already have these thoughts and plans in motion. So the basic layout of the Volt will be optimized for the future progress which is not that far in the future. 200 mile battery works for me!
As a Volt owner I want to say “What do I need gas for???”

By: Dave99

Dave99 — Wed, 16 Apr 2008 21:37:18 +0000

Reply to 2. FME III :
“E.G, a recent comment bemoaned the spoiler as adding drag. It is abundantly clear from the Volt team’s public comments that aero drag is one of the biggest factors they’ve had to overcome. Hence, I am sure that the spoiler is increasing aero efficiency or it wouldn’t be there.”

Actually, you’re right. In fluid dynamics (fluid = gas or liquid, you can use the same analysis for either), there are two type of drag:
1. surface drag (“pulls” along the surface of the vehicle, e.g. water trickling down an angled plate “tops out” at a certain speed speed, it doesn’t keep accelerating)
2. a front/rear pressure difference (“pushes” on the front of the vehicle [but not as much on the back], surface drag over the vehicle slows the air down and creates a lower pressure at the back of the car)

A spoiler will create a non-laminar/turbulent region at the back of the vehicle, which will mostly lead to less of #2, but a little less of #1 (source: my Fluid Mechanics class, and T. Gillespie’s book “Fundamentals of Vehicle Dynamics” http://www.sae.org/technical/books/R-114 )

A spoiler also creates rear downforce. Although significantly increased downforce leads to less efficiency, it may be necessary to keep the car stable at high speeds.

By: gr

gr — Wed, 16 Apr 2008 21:29:55 +0000

I too would want to have a greater than 400 mile E-REV range even if the added tankage weighed us down some. If you choose to use a flex fuel, e.g. E-85, and the infrastructure is not there yet, a single trip to the pump is far better than many. The marketing benefit of a 600 mile extended range will go far to support GM’s recent efforts in growing alternative fuel resources. Maybe a compromise?