On 10/08/2013 20:02, polygonum wrote:
That would tend to make the battery-carrying impact even more on the
stop-start/short range electric car than the fuel weight on long journeys.

In the stop-start scenario they can (and do!) use regenerative braking -
recharge the battery with the motors instead of throwing the energy
away. That's what they are really good at - that and not having a
tickover burning fuel even when sitting still.

But back a step - the weight difference between full and empty on my car
is perhaps 50Kg. Out of 1500. So ~3%. I don't notice it.

Andy