Electric Vehicles

I see another article about electric vehicles...and primarily about plug-in hybrids. And somehow the electric power grid has been replaced entirely with
green energy and demand for exported coal is ignored.
Of course I'm considering global warming rather then local or regional pollution...
But the idea IS elegant. The vehicle is plugged in overnight and then will drive for 40 miles before the internal combustion engine takes over. Then the metro commute is cleaner. (But again most of the plug-in electricity is produced by burning coal and the elegance is lost.) (And if we could avoid burning coal then the coal we don't burn is exported to be burned elsewhere.)
Now consider the most successful currently available all electric vehicle...the Tesla. That car costs $109,000, has two seats, and has a range of 220 miles. Now that car is successful both because it is a small car and because it is a car based on lightweight technology. Then the lightweight car with the batteries added becomes a car of average weight for its size.
Next consider the traditional hybrid vehicle. That vehicle depends on braking of the vehicle to charge the batteries. So that's a vehicle strategy that seeks to avoid lightweight technology. It accepts good charging action in exchange for less than possible efficiency when being driven by the internal combustion engine. Then the plug-in hybrid if its hybrid function is only plug-in...could use lightweight technology in the same way that the totally electric vehicle can !
But now realize that internal combustion engine vehicles can benefit from lightweight technology...in an astounding way. The car could be the size of a Altima, weigh 2200 pounds, use a 2.0 four-cyclinder engine as the premium engine, get 22/32 MPG, and maintain performance standards. Or the car could be the size of a Civic, weigh 1500 pounds, use a 1.0 three-cyclinder engine, get 35/50 MPG , and maintain performance standards.
But what is lightweight vehicle technology ? Well the frame and bodywork are separate, the frame is strong but pinpoint in fucntion and looks like a power transmission tower laid on its side, while the bodywork is lightweight and flexible but supported by the frame. Well the bodywork is very lightweight because the frame makes both lower an upper attachment points. And a bodywork of Lexan or Fiberglass or Royalex has good insulation properties.
However our current lightweight vehicle technologies work like a 2X4 laid laid across a ditch. With the 2X4 on its side it's bouncy but with the 2x4 laid on its edge its rigid. So the vehicle has two lower frame channels (hollow) turned up on edge. Then a fiberglass bodywork is attached to a frame that provides mostly lower bodywork attachments. And so the fiberglass bodywork is itself mostly rigid and not as lightweight as possible. (Okay the Corvette has a separate frame and bodywork and a fiberglass bodywork, the Elise has a separate frame and bodywork and a fiberglass bodywork, while the Solstice has a separate frame and bodywork but a steel bodywork.)
But the internal combustion engine in a lightweight vehicle is a good solution and a currently possible technology. Realize that the internal combustion engine has four valve heads (for less waste during the opening and closing of valves), electronic direct fuel injection, and mechanical variable valve timing. In other words don't throw away the internal combustion engine just as it gets very good...but put internal combustion engines in lightweight vehicles and use smaller engines.
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Oh the above mid-size car has a 2.0 premium engine or a 1.6 base engine. The 2200 pound mid-size car with the premium engine gets 22/32 MPG. The 2200 pound mid-size car with the base engine gets 28/38 MPG.
Then the above 1500 pound compact car with a 1.0 engine gets 35/50 MPG.
Now apart from the article I saw about an electric vehicle advocacy...GM has announced the Volt.
The Volt has four seats and a range of 40 miles on a 6 hour plug-in recharge. When the batteries run down a 1.0 (constant speed) internal combustion engine runs to charge the batteries while the car travels. The MPG while the batteries recharge off the internal combustion engine is about 50 MPG. The car looks to cost $40,000 to $50,000 with the first year production run of 10,000 vehicles.
Of course a car like the Volt can use a lightweight vehicle technology...and thus have fewer trade-offs of relevant fundamentals.

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Is it really going to be light weight? Hybrids pay a lesser penalty for weight, compared with IC cars. Without knowing any details it seems unlikely that GM can afford to develop a truly lightweight vehicle, as well as a somewhat innovative engine/motor/battery system.
The cost issue is interesting. Lutz has recently said that the realistic, unsubsidised selling price will be $48000. This is roughly 40% more than the cost that was announced a year ago. Hmmm
Cheers
Greg Locock
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I don't know the structural construction of the Volt...but an electric vehicle needs to use a lightweight technology and a strong frame technology because it will be heavy after the batteries are added. The EV can't begin with a premium rolling chassis weight and then add batteries.
But then an internal combustion vehicle can also benefit from a lightweight technology...just scale the engine size to the weight.
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I have a 3400 pound Honda CRV that gets 32mpg (actual measured value) and cost $25,000. An additional feature is that it has no batteries to change.
The electric vehicle, whether powered by plug in or Aux engine will have costly batteries to change. How long do the batteries in your lap top last before the available power starts to degrade? I, personally, notice that the laptop batteries only last about 3 years before the available power degrades. By the fifth year, the notebook can not hold a charge and must be plugged in continuously.
Electric cars will suffer from the same aging problem. The batteries will need to be replaced between 3-4 years. Cars with Aux engines will go longer, but the engine will be running more often to keep the aging batteries charged.
Jane
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I'm reading the Tesla web site for information...
I don't know but if the motor and transmission would last a million miles or something...I might not mind changing batteries for $10,000 or something...every five years or whatever.
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