C'mon that's a bit extreme.Just what the Hurricane pilots needed, less power for take-off and less power at altitude.
Why not just shoot the Pilots as they lined up next to their planes and save the gas ???
The Hurricane was essentially a low altitude ground attack aircraft from 1942 onward. I'm sure that Hurricane pilots would have preffered to fly with the Allison if they had Merlin engined Mustangs as an escort.