d ) gurgled happily, sounding much like they were saying :

Not to mention (Bendis) more fuel-efficient (due to their modern
engines) (than RMs)

Don't forget that all recent service RMs were rebuilt mechanically only a
very few years ago, and meet at least Euro2 emission standards.

The Citaro G Bendis are Euro3, but they *CERTAINLY* won't be "more fuel
efficient", due to the fact they weigh ELEVEN TONS more than a Routemaster.
That's before you consider the wasted time and fuel in traffic due to the
unwieldy extra length where a Routemaster would get through.