...[Tire makers are] coming under pressure as governments look for ways to make cars use less carbon-belching fuel... The European Union is expected to propose regulations that would set limits on tire rolling resistance... In California, legislators have passed a law calling for similar rules. In Washington, Congress is considering legislation that would create a consumer-information program on tire energy efficiency. The threat of new regulations has prompted a rush by established tire makers to block the most rigorous proposals... The focus on tires reflects a broader effort by governments to shift some of the burden of fuel-economy rules away from auto makers, which say job cuts and costly design changes will result from the most ambitious proposals to cut vehicle emissions... The problem, some industry officials said, is that reducing a tire's rolling resistance too much can weaken its traction or shorten the tire's life span. Germany's Continental AG said its tests indicate that tires designed primarily with low-rolling resistance in mind tend to have longer stopping distances on wet surfaces. [A U.S.] National Academy of Sciences study, however, reported that the safety consequences of reducing tire rolling resistance "are probably undetectable," and that a 10% reduction is "feasible and attainable within a decade" through new tire technologies and improved designs... Michelin SA is touting the fuel-saving potential of its "green tires."... This year, Michelin got a major boost when French car maker PSA Peugeot-Citroen SA adopted its fourth-generation "Energy Saver" tire for the new Peugeot 308 hatchback. Michelin officials say the tires will cut the car's carbon dioxide emissions by four grams per kilometer... The tire's braking distance on wet roads also is about 10 feet shorter than the previous-generation tire.