"Dave Plowman (News)" wrote in message
...
In article ,
Andy Burns wrote:
They don't have Otto cycle engine, instead Atkinson cycle engine, which
is more efficient though less powerful.

It's an interesting one. Like most hybrids, the IC engine does all the
work when at speed on a long journey. And an Atkinson cycle type is best
at a constant speed. Efficiency takes a dive outside this. Very noticeable
on early Prius which were very heavy on fuel when cruised at speed.

I was surprised at how little battery storage the Auris has (and this may be
true of other hybrids too), so it only uses the motor for a small amount of
the duty cycle - maybe a little bit more for lower speeds that you'd find in
town, so it would keep the towns cleaner at the expense of more pollution in
the countryside or on longer, faster journeys when the IUC engine also
charges the battery.

It sounds a good idea: design an engine that is as efficient as possible at
one speed, and then develop transmission that tries to maintain this engine
speed for a wide range of road speeds.

Are there any hybrids which are purely IC-electric (like diesel-electric
trains) where there is no mechanical connection between IC and wheels, just
a generator and electric motors. This would allow all the smoothness of
acceleration that you get with an electric motor, because the ratio between
motor and wheels is fixed (maybe 1:1), so there are no losses in a fluid
flywheel or in the belts of a CVT. On the other hand,
petrol-electric-kinetic is more energy conversions so there may be extra
losses in that.

At first, I assumed that a petrol/diesel-electric hybrid was like this: no
mechanical connection, only an electric one.