Automakers have long argued that to make fuel-efficient vehicles, they must compromise on safety, but a new report from the General Accounting Office contradicts that claim. The report, requested by Sen. John McCain (R-Ariz.), found little research linking tougher government fuel-economy standards with decreased vehicle safety. If given six to 10 years advance notice of higher fuel-economy standards, automakers should be able to increase the gas mileage of their fleets without simply building smaller, lighter cars that may be more dangerous for passengers during a crash.