fuel efficiency question

[O-D-C]

silicon said:

mrstickball said:

Electric vehicles have an efficiency of 80% or more. Regular cars are in the area of 20-30%.

The problem with combusion engines is that they do not convert gasoline (or most fuels for that matter) into energy very effectively. Electric motors are far more efficent, and certainly cheaper (cost per KwH vs. cost of fossil fuel), too.

Here is a pretty good breakdown:

http://www.fueleconomy.gov/feg/atv.shtml

For an electric car, you do not lose energy when idling (as the engine is not being turned), the engine does not lose any energy, and you usually have regenerative breaking. Therefore, the only losses are due to aerodynamics, accessories and drivetrain.

For the OP, I'd like to add that while the electric motor may be 80%, there are additional losses from charging the battery. Plus, depending on where you live, electricity can be generated using coal or natural gas which still has really low efficiencies.

Everything adds up. Efficiency is an odd thing. It's hard to compare since it's hard to know what boundaries to set.

true, but is the amount of energy used to power an electric battery for a 100km drive the same as driving a fossil fuel car for 100km?