The XP-46 was one of a series of attempts to improve the performance of the P-40 Warhawk, none of which entered production. Work began on the XP-46 in September 1939. It used a more powerful Allison V-1710-39 engine, capable of providing 1,150 hp at take off. The design was cleaned up to reduce drag, and a top speed of over 400 mph was predicted.
The XP-46A, with no guns, first flew on 15 February 1941. Performance was nowhere near as good as expected – the top speed was only 355 mph at 12,000 feet. This was only a very slight improvement over that of the P-40D then in production, certainly not a big enough improvement to justify disrupting production, and so work on the XP-46 was abandoned.