http://www.autonews.com/apps/pbcs.dll/article?AID=/20101004/RETAIL03/310049986At the bottom of the article...
"The 500's EPA gasoline mileage numbers have not been published yet. It will be the first North American vehicle to showcase Chrysler's MultiAir engine technology. Fiat says MultiAir improves fuel economy by 10 percent. That means the North American version should easily surpass 40 mpg compared with current European versions without MultiAir."
"Sources have told Automotive News that Fiat 500 test-drivers have achieved even better than that--50-plus mpg on Chrysler's test track in Chelsea, Mich."
Could be just a bunch of baloney...but who knows?