The Nissan Tiida 1.8 MR18 engine, more specifically the MR18DE, is a 1.8-liter, 4-cylinder, DOHC (Double Overhead Camshaft), 16-valve petrol engine that powered the Nissan Tiida in various markets, including South Africa. Known for its smooth operation and reliable performance, it was a common choice for those seeking a practical and dependable compact car.