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