WASHINGTON (AP) — Drivers will have to pay more for cars and trucks, but they’ll save at the pump under tough new federal rules aimed at boosting mileage, cutting emissions and hastening the next generation of fuel-stingy hybrids and electric cars.

The new standards, announced Thursday, call for a 35.5 miles-per-gallon average within six years, up nearly 10 mpg from now.

By setting national standards for fuel efficiency and greenhouse gas emissions from tailpipes, the government hopes to squeeze out more miles per gallon whether you buy a tiny Smart fortwo micro car, a rugged Dodge Ram pickup truck or something in between.

The rules will cost consumers an estimated $434 extra per vehicle in the 2012 model year and $926 per vehicle by 2016, the government said. But the heads of the Transportation Department and Environmental Protection Agency said car owners would save more than $3,000 over the lives of their vehicles through better gas mileage.

Touting the plan, Transportation Secretary Ray LaHood said, “Putting more fuel-efficient cars on the road isn’t just the right thing to do for our environment, it’s also a great way for Americans to save a lot of money at the pump.”

The requirements for the 2012-2016 model years pleased environmentalists who have criticized sluggish efforts by previous administrations to boost fuel efficiency. They also were welcomed by automakers who have been seeking a single standard after California and a dozen states tried to create their own rules.

Dave McCurdy, a former Oklahoma congressman who leads the Alliance of Automobile Manufacturers, a trade group representing 11 automakers, said the industry supported the single national standard for future vehicles. He said the program made “sense for consumers, for government policymakers and for automakers.”

Not all dealers were pleased. Ed Tonkin, a Portland, Ore., car dealer who chairs the National Automobile Dealers Association, said the rules were the “most expensive fuel economy mandates in history” and would turn many new cars and trucks into luxury items for consumers.

“Under these new mandates, the price of new cars and light trucks will rise significantly, meaning fewer Americans will be able to buy the new vehicles of their choice,” Tonkin said.

Environmental groups said the changes would actually give consumers more choices because they would ensure that every new car would get slightly more fuel-efficient each year.

“Because of these standards, Americans will drive vehicles that save them money at the pump, cut the country’s oil dependence and produce a lot less global warming pollution,” said Jim Kliesch, a senior engineer in the Union of Concerned Scientists’ Clean Vehicles Program.

The regulations set a goal of achieving by 2016 the equivalent of 35.5 miles per gallon combined for cars and trucks, an increase of nearly 10 mpg over current standards set by the National Highway Traffic Safety Administration. The figure could actually be as low as 34.1 mpg because automakers can receive credits for reducing greenhouse gas emissions in other ways, including preventing the leaking of coolant from air conditioners.

The changes will cost the auto industry about $52 billion, but the government says the program will provide $240 billion in savings to consumers, mostly through lower fuel consumption. The changes also could help U.S. manufacturers who produce advanced vehicles, batteries and engines, the government said.

The EPA is setting a tailpipe emissions standard of 250 grams (8.75 ounces) of carbon dioxide per mile for vehicles sold in 2016, equal to what would be emitted by vehicles meeting the mileage standard. This represents the EPA’s first rules ever on vehicle greenhouse gas emissions, following a 2007 Supreme Court decision.

Each auto company will have a different fuel-efficiency target, based on its mix of vehicles. Automakers that build more small cars will have a higher target than car companies that manufacture a broad range of cars and trucks. For example, passenger cars built by General Motors Co. will need to hit a target of 32.7 mpg in 2012 and increase to 36.9 mpg by 2016. Honda Motor Co., meanwhile, will need to reach passenger car targets of 33.8 mpg in 2012 and ramp up to 38.3 mpg in 2016.

Some small-volume auto companies such as Porsche, Aston Martin and Lamborghini will not have to meet the standards initially, but all automakers will need to comply by 2017.

Consumers can expect improvements to engines, transmissions and tires, and the use of start-stop technology that halts the engine at stop lights to save fuel. Automakers are expanding their portfolio of gas-electric hybrid vehicles and beginning to introduce electric cars and plug-in hybrids.

Nissan recently announced pricing for its electric car, the Leaf, which will be available in limited numbers later this year. Toyota is launching plug-in hybrids along with battery-powered cars running solely on electricity starting in model-year 2012.

In Michigan, the first version of the Chevrolet Volt, which can go 40 miles on battery power before an engine kicks in to generate power, rolled off the assembly line this week and is scheduled to be sold in limited numbers later this year.

Beyond electric cars, Ford is aggressively promoting its “EcoBoost” line of direct-injection turbocharged engines, which provide a 20 percent increase in fuel efficiency. General Motors will begin assembling the Chevrolet Cruze, a replacement for the Cobalt, in Ohio later this summer. The compact Cruze is expected to achieve about 40 mpg on the highway thanks to a 1.4-liter turbocharged engine.

“All the automakers are doing what we’re calling ‘downsize and boost.’ You take the engine, you make it smaller, you boost it, you put a turbocharger, a supercharger on it, and you get the same kind of results with better fuel economy,” said Aaron Bragman, an auto industry analyst with IHS Global Insight in Troy, Mich.

LaHood and EPA Administrator Lisa P. Jackson said the new requirements will save 1.8 billion barrels of oil over the life of the program. The new standards move up goals set in a 2007 energy law, which required the auto industry to meet a 35 mpg average by 2020.

EPA and the Transportation Department said the requirements would reduce carbon dioxide emissions by about 960 million metric tons over the lifetime of the vehicles regulated, or the equivalent of taking 50 million cars and light trucks off the road in 2030.

Environmental groups have sought curbs on greenhouse gas emissions, blamed for global warming, and they challenged the Bush administration for blocking a waiver request from California to pursue more stringent air pollution rules than required by the federal government. The request was granted by the Obama administration last year.