Americans are driving less, burning less gasoline, and buying fewer cars, and the feds have the stats to prove it. New numbers show that Americans drove 4.7 percent less in June 2008 than they did in June 2007, shaving off some 12.2 billion miles. For those keeping track at home, that makes a total 53.2 billion fewer miles driven between Nov. 2007 and June 2008 than in that eight-month period a year earlier. As would be expected, gasoline and diesel use have also fallen: In the first three months of 2008, Americans burned 400 million fewer gallons of gas than they did in the first three months of 2007, as well as 318 million fewer gallons of diesel. And easing off the gas pedal has eased oil demand as well: In the first half of 2008, U.S. demand for oil fell by an average 800,000 barrels per day compared to the first half of 2007, the biggest decline since 1982. Not to be left out, sales of cars, trucks, and vehicle parts fell 2.4 percent from June to July. So dust off that bike and join the trend.