A lubricant tank for a lubrication system of a snowmobile engine includes an upper portion and a lower portion. The upper portion is enlarged relative to the lower portion. A recess is defined on an engine side of the lubricant tank by a lower surface of the upper portion and a lateral surface of the lower portion. The recess accommodates a protruding portion or component of the engine. The tank also comprises a sloping surface that extends between the upper portion and the lower portion inside the tank. Lubricant is returned in the upper portion and transferred to the lower portion through a zigzag flow path.