Americans are adopting this message. The latest Motorcycle Industry Council Owner Survey found that, among reasons for riding, "commuting and errands" jumped to the No. 2 spot only behind "riding for pleasure." In 2008, as gas prices topped $4 a gallon, scooter sales rose to 222,000 for the year – the highest level yet seen by the MIC.There are far more riders than ever. The number of American households that own motorcycles jumped 26 percent from 2003 to 2008, while the overall number of U.S. households increased roughly 5 percent. During the same period, the motorcycle population grew 19 percent while the U.S. population rose by about 5 percent. Some 25 million Americans swung a leg over a bike and rode last year. That’s a 7 percent increase, from 2003, in the number of people who ride but may or may not own motorcycles.SAVING GREEN>> Motorcycles cost much less to buy. There are many fine, capable bikes available for less than $4,000.>> Maintenance costs are much less on a bike.>> Registration is less money.>> So is insurance.BEING GREEN>> Hundreds or even thousands of pounds less in raw materials, and that can include the toxic elements used in hybrid car batteries.>> Less energy required to ship a motorcycle from factory to dealership.>> With smaller engines and fewer components, there’s less use of motor oil and chemicals throughout the life of a bike.>> Less use of gasoline, as a motorcycle or scooter can get two, three, sometimes four times the MPG of four-wheelers using the same roads. Many motorcycles can deliver 50 to 70 miles per gallon. Many scooters can return 60 to 80 MPG.>> Less fuel use means less CO2 emissions, now recognized as a pollutant and long known to cause climate change.