ORIGINAL: Robrow
...
JMP have gone to a lot of trouble to design a lovely smooth jet to minimise drag wherever possible but a fatter engine with lower exhaust velocity would negate a lot of that work.
...
Fatter engines do not necessarily have lower exhaust velocities. The velocities of all engines are around 600-700mph so the issue is really moot.
Fatter engines usually have better fuel economy - means smaller tanks - more room for engine
It blows my mind to think that manufacturers go for slimmer motors with more thrust per weight (of the engine) instead of maximizing efficiency. People tend love to buy those high T/W engines and then negate the whole thing by putting in much more fuel! Better to have 200 more grams of motor than carry 1000 in fuel IMHO.