Several people I've met recently have told me they are considering a motorcycle to save money on gas. That got me thinking about the economics of fuel savings when operating a motorcycle. For the purposes of this discussion, I'll not include sidecars/hacks, because this would simply make things more complicated.
Operating a motorcycle solo or two up IS more econimical than driving a car, however; there is more to it than that. We are much more prone to ride our bikes merely for the sake of enjoyment as much as for transportation, therefore, the gas we burn while riding is often an unnecessary expense. This must be added to the equation when considering the economics. For example, a motorcycle may have an average MPG or 'fuel burn' of 40 MPG. While on the surface, this looks as though it may be as much as twice the efficiency of a car which may have a combined average MPG rating of 20 MPG, but the motorcycle may have been driven twice as much as the car has, since half of that mileage is 'recreational.' Therefore, the economics of a 40 MPG bike is reduced to the same as a car burning 20 MPG, since the bike in this example is used as much for recreation as for basic transportation.
Another example would be that a single 40 MPG bike carrying two people gets twice as much MPG as a car averaging 20 MPG and carrying two people. However, again, the 'recreational' part plays a role. If, for example, three buddies take off on their respective 40 MPG motorcycles on an 80 mile ride, the trip will burn 6 gallons to convey three people. Now, a 20 MPG car carrying 3 people 80 miles will burn 4 gallons of fuel. In this example, a car was a more economical way of carrying three people than each person riding his/her own bike.
