An endless drive arrangement of an engine including a crankshaft pulley driven by a crankshaft, a motor/generator unit pulley, and an endless drive member entrained about the crankshaft pulley and the MGU pulley, wherein the endless drive arrangement is operable in a first mode in which the crankshaft pulley drives the endless drive member and the MGU pulley does not drive the endless drive member such that tension in a first span of the endless drive member is lower than a second span of the endless drive member, and wherein the endless drive member is operable in a second mode in which the MGU pulley drives the endless drive member in isolation or in conjunction with the crankshaft pulley, wherein the endless drive arrangement further comprising a tensioner comprising: a first tensioner arm that is pivotable about a first arm pivot axis and which has a first tensioner pulley rotatably mounted thereto for rotation about a first tensioner pulley axis that is spaced from the first arm pivot axis, wherein the first tensioner pulley is configured for engagement with the first span of the endless drive member; a second tensioner arm that is pivotable about a second arm pivot axis, which is spaced apart from the first arm pivot axis, and which has a second tensioner pulley rotatably mounted thereto for rotation about a second tensioner pulley axis that is spaced from the second arm pivot axis, wherein the second tensioner pulley is configured for engagement with the second span of the endless drive member; a tensioner biasing member that is positioned to bias the first and second tensioner arms (30, 32) in a first free arm direction and in a second free arm direction, respectively, wherein the first tensioner pulley is disposed on a first side of the first tensioner arm pivot axis, and the tensioner biasing member is positioned to apply the tensioner biasing force on a second side of the first tensioner arm pivot axis, and wherein the second tensioner pulley is on a first side of the second tensioner arm pivot axis, and the tensioner biasing member is positioned to apply the tensioner biasing force on a second side of the second tensioner arm pivot axis; wherein the endless drive arrangement is characterized by a second tensioner arm stop surface that is positioned to limit the movement of the second tensioner arm in a direction opposite the second free arm direction, wherein a geometry of the tensioner is such that the second tensioner arm has a preload applied by at least the endless drive member and the tensioner biasing member, wherein the preload urges the second tensioner arm into engagement with the second tensioner arm stop surface such that, in use, the second tensioner pulley is engaged with the endless drive member while the second tensioner arm is engaged with the second tensioner arm stop surface in the first mode of operation. a first tensioner arm that is pivotable about a first arm pivot axis and which has a first tensioner pulley rotatably mounted thereto for rotation about a first tensioner pulley axis that is spaced from the first arm pivot axis, wherein the first tensioner pulley is configured for engagement with the first span of the endless drive member; a second tensioner arm that is pivotable about a second arm pivot axis, which is spaced apart from the first arm pivot axis, and which has a second tensioner pulley rotatably mounted thereto for rotation about a second tensioner pulley axis that is spaced from the second arm pivot axis, wherein the second tensioner pulley is configured for engagement with the second span of the endless drive member; a tensioner biasing member that is positioned to bias the first and second tensioner arms (30, 32) in a first free arm direction and in a second free arm direction, respectively, wherein the first tensioner pulley is disposed on a first side of the first tensioner arm pivot axis, and the tensioner biasing member is positioned to apply the tensioner biasing force on a second side of the first tensioner arm pivot axis, and wherein the second tensioner pulley is on a first side of the second tensioner arm pivot axis, and the tensioner biasing member is positioned to apply the tensioner biasing force on a second side of the second tensioner arm pivot axis; wherein the endless drive arrangement is characterized by a second tensioner arm stop surface that is positioned to limit the movement of the second tensioner arm in a direction opposite the second free arm direction, wherein a geometry of the tensioner is such that the second tensioner arm has a preload applied by at least the endless drive member and the tensioner biasing member, wherein the preload urges the second tensioner arm into engagement with the second tensioner arm stop surface such that, in use, the second tensioner pulley is engaged with the endless drive member while the second tensioner arm is engaged with the second tensioner arm stop surface in the first mode of operation.