Carmakers will show off their greenhouse-gas-busting technologies March 8-18 at this year’s Geneva International Motor Show. This is not merely an exercise of engineering prowess. After automakers failed to meet voluntary agreements to cut average emissions from new cars to 140 grams of carbon dioxide per kilometer, EU environment ministers appear ready to set tougher, mandatory limits.

Historically, diesel has played a key role in Europe’s fuel efficiency strategy, and the Geneva show will feature a number of greener cleaner diesels. But the real news could be BMW’s introduction of mild hybrid technology, even though they are not using the “H” word. Hybrids have been slow to take hold in Europe. In 2006, there were fewer than 16,000 hybrids sold in the U.K. and France combined—compared to 250,000 hybrids sold in the United States.

The effects of new low-carbon rules will be long lasting. The first target is 2020, when greenhouse gas emissions must be reduced by 30 percent of 1990 levels. Then, carmakers must cut further to 60-80 percent of 1990 levels by 2050. "The bulk of the effort will have to come from vehicle motor technology,” said EU spokesman Johannes Laitenberger.

BMW’s 1-series Mild Hybrid

Americans are not familiar with BMW’s diminutive 1-Series, the company’s ultra-popular entry-level subcompact hatchbacks available in Europe since 2004. BMW has created a sportier design for the three- and five-door BMW 1 Series—and is introducing the lineup in Geneva to champion its comprehensive package of fuel saving technologies: variable valve timing, electric power steering, low resistance tires, lightweight materials, improved aerodynamics, gearshift change indicators, and most notably, an auto-stop function with regenerative braking.

What does all this add up to? According to BMW, the four-cylinder 118d achieves 0-60 mph performance in less than eight seconds, while achieving a combined fuel economy of nearly 50 miles per gallon.

BMW’s version of the auto-stop function, a feature found in hybrids in the American market, allows drivers to avoid burning any fuel when the driver applies the brakes or slips the vehicle into neutral. Step on the gas or reengage the clutch, and the engine is immediately available for duty. BMW is treating the auto-stop function, and all the other fuel-saving measures, as improved “conventional” technologies, rather than something worthy of a dedicated green marketing campaign.

Furthermore, BMW will introduce auto-stop in a broad model range, including four- and six-cylinder 1-, 3- and 5-Series models—and in the Mini Cooper. Klaus Borgmann, senior vice president of powertrain development for BMW, said the auto-feature is being evaluated for use in North America.

The new BMW 1-Series goes on sale in Europe this spring 2007. Automobile magazine reports that the 1-series will hit U.S. shores as a 130i coupe in 2009.