In article
,
Neil Williams wrote:
One advantage is that a diesel engine acting as a generator to charge
the battery can always, when running, operate at maximum efficiency.
One running up through the gears varies in efficiency (try driving a
car with an instantaneous MPG readout).

Many of the newer buses have multi-speed autos. I've counted 6 gear
changes on some at town speeds. I'd expect they don't have a torque
convertor - or lock it up - so should be much more economical than once.

--
*You never really learn to swear until you learn to drive *

Dave Plowman London SW
To e-mail, change noise into sound.