A multi-cylinder engine for a motor vehicle comprises at least two cylinders mounted in mutually displaced relationship with respect to longitudinal and transverse directions of the vehicle. The crankshaft for one of the cylinders is located at a higher level than the crankshaft for the other cylinder. A crankcase assembly of the engine is vertically divided into pieces by a plurality of planes extending perpendicular to the crankshafts and each plane passing through each center of the cylinders. The engine provides first and second gears mounted on the primary shaft, a crank gear for one of the crankshaft, a crank gear for the other crankshaft, and an idle gear. The first gear is in meshing engagement with the crank gear for one of the crankshaft, while the second gear is connected to the other crank gear through the idle gear.