Working to boost car mileage

The first modern mass-market electric cars will cause a sensation when the Chevrolet Volt and Nissan Leaf go on sale later this year, but a quiet revolution in engines and transmissions promises to save vast amounts of oil in the decades before electric vehicles rule the road. • Even electric vehicles' ardent supporters concede electric vehicles will only be a tiny slice of the total vehicle fleet for years to come, but Chrysler, Ford, GM and Volkswagen are poised to deploy fuel-saving systems in millions of vehicles. Some are already on the road. Many more will be within a year. • Here's a primer on where they'll show up first. Mark Phelan, Detroit Free Press

Eight-speed transmissions. Already available on BMW and Jaguar luxury cars, they'll go mainstream next year when Audi starts installing them in nearly every vehicle it builds. In 2013, Chrysler is to begin building them in Indiana. Look for them in Ram trucks and the 300 and Charger sedans.

Dual-clutch transmissions. Already available in the Fiesta, coming soon to Chrysler, Dodge and Jeep. A six-speed dual-clutch gearbox helps the subcompact Fiesta get 40 mpg on the highway. They use computer controls to change the gears of a transmission that has most of the same parts as a manual gearbox. There's no clutch pedal, however. The driver can leave the selector in drive while the computer handles the shifting.

Turbocharging and direct injection. Already available in the Ford Taurus SHO, Lincoln MKS and a wide range of Audis and VWs, this combination boosts the power of small engines. That lets automakers use smaller and more fuel-efficient engines without sacrificing performance. A DI turbo engine will lift the roomy Chevy Cruze's EPA rating to 40 mpg. Ford already uses the system with V6s and will add it to four-cylinder engines to reduce fuel consumption in the new 2011 Explorer. Look for it to become common in all sizes of vehicles.

Diesel. European automakers lead in this technology, which combines good acceleration with excellent fuel economy. Audi, BMW, Mercedes-Benz and VW will promote their diesels heavily. American and Asian companies have bet more heavily on electric vehicles and improving gasoline engines' fuel efficiency. If electric vehicles do account for 10 percent of the market by 2020, it's a safe bet that they'll outsell diesel cars here by a wide margin.