An apparatus for an engine having a cylinder head (3L,3R) and a cylinder block, the apparatus comprising: an oil pan and an oil return path for returning oil supplied to the cylinder head to the oil pan, the oil return path including at least one oil return main path (11L, 11R) disposed at a first side surface of the cylinder block and at least one oil return extension r path (12L, 12R); wherein the at least one oil return extension path includes an upstream end and a downstream end, the upstream end being connected to the at least one oil return main path and the downstream end being positioned at a distance from the first side surface of the cylinder block such that the oil return extension path extends in a direction of a second side surface of the cylinder block; wherein at least a portion of said at least one oil return extension path is defined by a portion of the oil pan; wherein the at least one oil return extension path includes a plurality of oil return extension paths wherein the oil pan comprises a shallow bottom portion and a deep bottom portion, characterised in that the plurality of oil return extension paths are provided in parallel between the shallow bottom portion and the deep bottom portion, and wherein the plurality of oil return extension paths are defined by upper surfaces, and the upper surfaces form the bottom surface of the oil pan that becomes deeper in steps from the shallow bottom portion to the deep bottom portion; and wherein the plurality of oil return extension paths includes first (121L,121R) and second (122L,122R) oil return extension paths and wherein the first of the oil return extension paths is formed such that a portion of an upper surface thereof is substantially flush with and/or lower than the shallow bottom portion. an oil pan and an oil return path for returning oil supplied to the cylinder head to the oil pan, the oil return path including at least one oil return main path (11L, 11R) disposed at a first side surface of the cylinder block and at least one oil return extension r path (12L, 12R); wherein the at least one oil return extension path includes an upstream end and a downstream end, the upstream end being connected to the at least one oil return main path and the downstream end being positioned at a distance from the first side surface of the cylinder block such that the oil return extension path extends in a direction of a second side surface of the cylinder block; wherein at least a portion of said at least one oil return extension path is defined by a portion of the oil pan; wherein the at least one oil return extension path includes a plurality of oil return extension paths wherein the oil pan comprises a shallow bottom portion and a deep bottom portion, characterised in that the plurality of oil return extension paths are provided in parallel between the shallow bottom portion and the deep bottom portion, and wherein the plurality of oil return extension paths are defined by upper surfaces, and the upper surfaces form the bottom surface of the oil pan that becomes deeper in steps from the shallow bottom portion to the deep bottom portion; and wherein the plurality of oil return extension paths includes first (121L,121R) and second (122L,122R) oil return extension paths and wherein the first of the oil return extension paths is formed such that a portion of an upper surface thereof is substantially flush with and/or lower than the shallow bottom portion.