Dave Plowman (News) wrote:

In article .com,
wrote:
AIUI the point is that it is (or can be) a more efficient IC engine
powered car since the IC engine can always be run under the most fuel
efficient conditions instead of being geared to the road wheels.

Only while there's some battery charge. Once that is exhausted, the petrol
engine is effectively driving the wheels direct, but via a generator and
electric motor or some form of split drive. Hence the poor consumption
under those conditions.

So am I right in thinking that (roughly speaking) for continuous running a
conventional system is more efficient, whereas doing a lot of shuffling
along in heavy traffic a hybrid can be better? Has anyone done the figures
(for current production technology conventional and hybrids) to work out
which would be better averaged out over national traffic patterns? In other
words, if you were to replace the entire national car fleet overnight with
equivalent hybrids would net fuel consumption increase or decrease?