On Dec 21, 2:30*am, Bill Wright wrote:

And how much energy will that provide? The energy wasted when braking is
very small. Most fuel is used combating rolling resistance and wind
resistance. London is not the sort of place where buses drop down long
hills on their brakes.

If the driver anticipates properly very little energy is wasted in
braking for traffic conditions.

London buses in London traffic would never get anywhere if the drivers
drove solely using the accelerator and engine braking.

Elsewhere, maybe, in less congested cities, and coaches on motorways,
yes.

Better to start a bonus scheme where the
driver's pay is linked to his fuel consumption. That's the scheme all
the self-employed are on, and believe me it works.

A lot of bus companies are fitting "green driving" devices to achieve
exactly that.

So given that the process of generating electricity, storing it in
batteries, and then using it to drive motors is highly inefficient, how
is this going to save diesel? Don't forget the weight of the batteries
has to be lugged around as well. Bonkers!

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).

One thing that might be interesting is also the question of whether a
hybrid arrangement or a slushbox is more efficient. Buses tend, out
of practicality, to use automatic gearboxes with fluid couplings.
While some coaches now use automatically-operated standard clutch-
fitted gearboxes ("Tiptronic"-type things) which are more efficient,
these aren't as good for city buses because of the constant stop-start
and the fact that you lose power for a short time as the gears change,
which might be less safe in a city setting.

Neil