The numbers are eye-popping. The government wants new vehicles sold in the 2016 model year to average 35.5 mpg vs. 25.3 mpg this year.
So does this mean that U.S. roads will look like Europe's — a sea of small and smaller cars with hardly a pickup or SUV in sight?
No. The new-vehicle fleet in 2016 will look remarkably similar to today's lineup, with pickups, SUVs and large, medium and small cars. But plenty of changes are coming under the hood.
The next decade will be an era of painful cost choices: Automakers may remove content from interiors, for example, as they add hybrid technology and other fuel-saving devices to the powertrain.
A key question is whether automakers can persuade American consumers — who until now have equated small with cheap — to pay extra for small, high-mileage cars.
As the fuel-saving rules, announced by the Obama administration last week, take hold, here are significant changes that industry sources and analysts see in the next decade:
-- Supplies of V-8-powered cars and trucks will be limited — and their stickers may rise substantially.
-- Pressure to cut costs will intensify as automakers add equipment, such as turbochargers and hybrid powertrains, to reduce fuel consumption. Last week the White House said the average sticker will be $1,300 higher in 2016.
-- Expect more hybrids, electrics and perhaps diesels, as the government encourages alternative powertrains.
The good news is that technologies to reach the new goals are on the shelf. The problem is they add costs.