"Claus Gustafsen" wrote in message
.. .
Funny you say a poor performer - I have read the opposite, that it flew
both higer faster and longer than either Mk I or III.

The Lancaster Mk II equipped with the Hercules XVI
had a similar speed to the Merlin powered ones, but
were restricted to a servce ceiling, just above 15,000 ft.
at maximum weight, with a higher fuel consumption.

Ref: Avro Lancaster The Definitive Record by Harry Holmes