A snowmobile includes a nose cone having an underbelly, first and second side walls and a top cover together defining a substantially conical enclosure for enclosing a forward end of the snowmobile. The top cover includes a pair of air inlets for admitting air into the engine compartment as well as air guides connected to the inlets for directing the air to desired regions of the engine compartment for improving engine performance. The top cover also includes grilles for filtering out snow and other debris. Furthermore, the air guides are designed to suppress engine noise.