On 6 Jul, 11:15, Boltar wrote:
On 6 Jul, 11:05, Adrian wrote:

Don't forget that the engine is basically just being used as a generator,
therefore can run at optimum revs for the specific output - there's no
requirement for any kind of useful rev range or torque curve.

True , and I suppose that will mitigate it somewhat. However
ultimately that engine will produce less power than a normal bus
engine so when relying on the engine alone its going to be slower
compared to the normal engine running at optimum gearing.

B2003

You might be right for an outer suburban bus route, or one going from
town to town. However, a bus in London will probably average about
15mph. Hypothesising a little, if a 6 litre engine can deliver 60mph,
a 1.5 litre engine should deliver 15mph. The battery is being used as
an accumulator so average speed determined average power requirement.