California aims to double greenhouse gas emissions cuts and fuel efficiency gains in a new round of regulation for vehicles that will start late this decade and may spur draft federal goals later this year, the state's top climate change regulators have said. The new round in 2017-2025 could have similar cost consequences as the national standards adopted on 1 April for model years 2012 to 2016, adding about $1,000 per vehicle in cost and delivering fuel savings of around $3,000, they said. California is uniquely able to set pollution standards for cars, and the environmentally minded state was ahead of the federal government in folding carbon dioxide and other climate-warming greenhouse gases into regulated pollutants. Federal standards will cut average vehicle greenhouse gas emissions to 250 grams per mile and improve fuel economy to 35.5 miles per gallon for 2016 models, according to the US Environmental Protection Agency. More than 60% of US oil consumption and over 25% of domestic carbon pollution comes from cars and trucks, environmental statistics show. California is keen to lead the next round of vehicle rules, building on a 30% improvement in greenhouse gas emissions compared with California's base year of 2009. "We think we can sort of double the reduction," said Tom Cackette, the board's chief deputy executive officer and head of car regulation. He forecast a 50-60% improvement versus 2009 in greenhouses gases. Gains in fuel efficiency, not covered by California rules, would be similar, he said. "We still think we are in that curve where costs will be much less than the economic benefits derived in fuel savings," he added. "There's nothing here for the next stage that is something that requires a wild invention of something new." The goals could be announced at the end of September and turned into rules for greenhouse gas emissions and fuel economy by mid-2012.