On Mon, 19 Nov 2007 23:51:55 -0500, Orval Fairbairn
wrote in
:

In article ,
Larry Dighera wrote:


200 watt-hours = 682 BTU. Since there are about 115,000 BTU in a
gallon of gasoline, that implies that the electric car would get the
equivalent of 168 miles per gallon, ignoring efficiency differences.

Ignoring the efficiency differences between a vehicle powered by a
gasoline powered IC engine and an electric motor is useless. Consider
the IC engine converts about 25% of the energy in it's fuel into
useful power. I don't know the efficiency of the Volt electrical
power system, but it could be as high as 95%. Add to that the energy
recovered by regenerative braking...

Regenerative braking is a fantasy! Batteries are not set up to take
high-wattage charging, which is what regenerative braking really is. In
addition, the assumption of RB is that braking is a slow process; in
reality, it is a rather fast process, where the energy of motion is
converted to heat, through the brakes.

You are correct to suspect the physics of regenerative braking, but
that doesn't mean it can't be done. The electricity generated by the
motor when the brakes are applied is stored in a low impedance
capacitor. There's some information about the technique used on an
electrically powered vehicle that has no brakes he

http://www.gizmag.com/go/6104/1/
Another of the tricks employed by PML is the use of a 350V, 11
Farad ultracapacitor. Capacitors are used to store electrical
energy and can release/absorb their energy 10 times faster than a
battery. Using an ultracapacitor means that acceleration or power
boost at higher speeds can get energy twice as fast at peak draw,
offering “nitro-like performance.”