The Circle L is an automobile engine produced by GM Powertrain Poland in Poland. It is a 1.7 L; 102.9 cu in (1,686 cc) inline-four 16-valve turbocharged diesel engine originally designed by Isuzu but now owned by General Motors. The engine was produced in Europe by General Motors for use in the Opel, Vauxhall and Chevrolet vehicles and by Honda for use in the Civic compact car.
The engine kept the same dimensions of 1.7 4EE1. The main differences are in the DOHC camshafts and direct injection. The first engines mounted a simple direct injection and met the Euro 3 standard, while the later engines met Euro 4 and used common rail injection technology. The 1.7 Circle L common rail engines were the first common rail engines used in Opels.