The poly-V engine components single drive belt (1) drives the alternator (2), the power assisted steering pump (3) and the air conditioning compressor (4).The belt is tensioned by a tensioner cam (5) for the preload and automatic tensioner (6) and does not require servicing.The crankshaft pulley contains a flexible sector that reduces crankshaft torsional vibration and stresses on the belt and thus on auxiliary engine components.