Jonathan/Yoni's insightful post on Sunday highlighted a limitation of electric cars. He calculated that a gasoline pump transfers energy to your car at a rate of around 22 megawatts. According to Wolfram|Alpha, this is around 3667-7333 average households' power consumption, or just over half the total power output of the largest US photovoltaic power plant.
This would be amazing if cars utilized 100% of the thermal energy output of gasoline combustion. But, automobile engines (like all heat engines) can not operate at 100% efficiency. According to Wikipedia, car engines operate at 15-20% efficiency.[wiki quoted source] This means that before anything else is taken into consideration, it's an order of magnitude less useful energy transferred. Electric motors, on the other hand, have efficiencies which approach 100%![source] So, even if the rate of energy transfer to the car is slow, the real question is what is the effective (useful) power.
For example, our Ford Focus gets 40mpg on the highway.[source] So, it's "usefulness speed" is: (40 miles/gallon)*(10 gallons/min) = 400 miles/minute, which works out to 24,000mph! A Ferrari 599 GTB Fiorano "usefulness speed" is (15 mpg)*(10 gpm) = 150 miles/minute, or 9,000 mph [source] The Prius, at 48mpg is 480 miles/minute, or 28,800 mph. [source]
The Nissan Leaf, with a range of 100 miles/charge and a greater than seven hour home charge time (under ideal circumstances), has a useful speed of 0.23 miles/minutes, which is only 14 miles/hour. That makes it 0.05% as useful as my car, and 0.16% as useful as a Ferarri!
So, instead of focusing on top speed when buying a car, you can focus on top usefullness speed! You can even go one step further and look at top usefullness speed/cost. And, I agree with Jonathan/Yoni's conclusions: Until batteries and their charging methods improve drastically, gasoline wins by a landslide.
Note: I was trying to do these calculations with the Chevy Volt, but it requires a few too many assumptions.
Also Note: If anyone wants to estimate what a bicycle's useful speed is, the comments are open!