Circle L engine: Automobile, Isuzu Motors Polska, Diesel engine, Inline-four engine, Isuzu, General Motors, Opel, Vauxhall Motors, Honda, Opel Astra, ... Opel Corsa, Opel Meriva, List of GM engines

The Circle L is an automobile engine produced by Isuzu Motors Polska in Poland. It is a 1,686 cc (1.686 L; 102.9 cu in) Diesel straight-4 originally designed by Isuzu but now owned by General Motors. The engine is used in Europe by GM's Opel and Vauxhall subsidiary and by Honda.