The N181 is a racecar that was constructed and entered by Ensign during the 1982 season of F1. It was driven by Roberto Guerrero.
The car was fitted with a 3000cc Ford Cosworth DFV V8 engine and had a Hewland FGA 400 five-speed gearbox. The car had an aluminum/carbon fiber monocoque chassis and rode on Avon and Pirelli tires.
The car debuted at the 1982 Brazil GP, where it didn't qualify. The last race the car was entered in was the 1982 Las Vegas GP, where it was retired due to engine failure. The car did not have a very successful career, only having completed one out of the fourteen races it was entered in.