A third I-230 airframe was completed early in 1943 with an 1800hp Mikulin AM-39 12-cylinder Vee-type engine and the Izdeliye designation 2D. Apart from the tailplane which was set 20cm lower, this aircraft was basically similar to the first I-230 and retained the same armament of twin synchronised cannon. Assigned the official designation of I-231, the prototype was written off in a landing accident shortly after the completion of factory testing and further development was discontinued.
Engine: 1800hp Mikulin AM-39
Max take-off weight: 3287 kg / 7247 lb
Empty weight: 2583 kg / 5695 lb
Max. speed: 707 km/h / 439 mph
Range: 1350 km / 839 miles