The fuel efficiency of a Can-Am Ryker will depend on the specific model and year of production, as well as the operating conditions and how the vehicle is ridden. In general, the Can-Am Ryker has a fuel efficiency of around 40-50 miles per gallon. However, it is important to note that the actual fuel efficiency of any vehicle can vary based on a number of factors, including the terrain it is being driven on, the speed at which it is ridden, and the rider's style. It is always a good idea to check the manufacturer's specifications for the specific fuel efficiency of your particular model of the Can-Am Ryker.