The N173 is a racecar built by Ensign and entered into the 1973 F1 Season. The car was driven by Rikky von Opel.
The car had a Ford Cosworth DFV V8 engine and a Hewland 5-speed manual gearbox.
The N173 made its debut at the 1973 French GP and competed at its last race at the 1974 Argentine GP. The car did enjure much success and was soon replaced by the Ensign N174.