The engine that is installed in a Can-Am Defender will depend on the specific model and year of production. The Can-Am Defender is available with a range of engine options, including gasoline, diesel, and hybrid powertrains. The specific engine that is installed in a particular model of the Defender will be determined by the manufacturer and will be specified in the vehicle's specifications. It is always best to refer to the manufacturer's specifications for the specific engine that is installed in your particular model of the Can-Am Defender.