In message , Dave Plowman
writes

They're still incredibly inefficient compared to a decent electric
motor - energy in against energy out.

Also, the difference between a petrol and diesel of similar output both
at full power isn't that great.

--
Whilst both are true, electricity has to be generated somewhere and
that's where the losses occur. As for Petrol v Diesel, neither are
driven flat out for very long in the life cycles but the efficiency of
the unloaded Diesel far exceeds the unloaded Petrol at similar low
powers.
--
Clive