The AGS JH21C was a Formula One car designed by Christian Vanderpleyn and Michel Costa for use by the AGS team in the 1986 Formula One season. The driver was Italian Ivan Capelli.

The single JH21C was built around an old Renault RE40 monocoque which Julien had acquired. Its chassis number was 031.

The car was also tested by Didier Pironi who drove an F1 car for the first time since his awful accident in 1982, but decided against a return.

The engine was a Motori Moderni turbocharged V6. The team's main sponsor was El Charro (a Mexican shoe and clothing company).

It made its debut at the Italian Grand Prix where Capelli qualified in 25th place, but retired after 31 laps with a puncture.

After Formula One

The JH21C was not used in Formula One racing after 1986. The car is now on display at the Lohéac Automobile Museum.