A snowmobile has an internal combustion engine that includes a lubrication system. The lubrication system includes a lubricant pump unit mounted in a crankcase chamber of the engine, a lubricant cooler, and a lubricant filter. The lubricant pump unit is mounted at a location offset from an axis about which the crankshaft rotates. The lubricant pump unit also has a lubricant pump that is rotatable about a lubricant pump axis. At least one of the lubricant cooler and the lubricant filter is positioned on the same side of the engine as the lubricant pump unit.