at guidonia, the aircraft was tested like the many other fighters present for evaluation. however, it was only tested against the fiat cr.42 "falco", the only other biplane. in mock fights the ca.165 outperformed the cr.42, thanks to the superior aerodynamics and available power. despite this, the aircraft was rated inferior as the cr. 42 was more maneuverable and employed a reliable powerplant while the caproni engine was experimental and had poor reliability. however, the ca.165 was declared the "winner" of the mock fights, so general valle ordered 12 examples on 2 september 1939, although the order was cancelled on 11 october 1939 and changed to 12 caproni f.5s. this production shift was made even though it involved the payment of a penalty.