An exhaust system for a snowmobile includes a muffler housing, the bottom end of the muffler housing including a muffler exhaust outlet configured to emit exhaust. The exhaust system includes a muffler housing cover spaced from the muffler housing to define an airflow channel therebetween, the muffler housing cover forming a bottom opening. The exhaust system also includes a gas combiner at least partially surrounding the muffler exhaust outlet on the bottom end of the muffler housing and extending through the bottom opening of the muffler housing cover. The gas combiner receives air from the airflow channel and the exhaust from the muffler exhaust outlet to emit a combined air-exhaust stream.