The next thing in greener cars doesn’t need hydrogen, lithium-ion batteries or even a power cord. In fact, it’s based on century-old technology that’s been used on trucks since before World War II: the turbo.

Under pressure to reduce emissions and increase fuel-efficiency, automakers are quietly turning to turbocharging as a relatively cheap, easy-to-implement technology that could soon be a permanent staple on internal combustion engines.

That’s because turbos, high-velocity fans that recirculate and compress exhaust gases back into the motor’s cylinders, can increase fuel-efficiency by as much as 30% while increasing power output. Thanks to that increased power, smaller engines can be used, reducing weight and further increasing efficiency. And because it’s a proven technology, the research and development costs are enticingly low.

FOR THE RECORD:

Turbochargers: An article in Business on Saturday about turbochargers described them as compressing exhaust gases back into an automobile motor’s cylinders. A turbocharger uses exhaust gases to drive a compressor that in turn delivers pressurized air into the engine intake.



“There isn’t a dynamometer in Detroit that doesn’t have a turbocharged engine being tested on it right now,” says Eric Noble, president of Carlab, an automotive consultant in Orange. “There’s still a lot of fuel savings that can be gotten out of a traditional engine.”

Automakers are cagey about announcing how many cars will get the turbo boost, but General Motors executives say they are considering putting turbos on even their largest passenger vehicles. Hyundai just announced its first turbocharged car -- the Genesis coupe -- for the U.S. market in a dozen years.

Volkswagen and Mercedes-Benz are preparing to hit the American market with new turbocharged diesels starting next year. And last week at the L.A. Auto Show, Ford Chief Executive Alan Mulally announced a major initiative to begin putting turbochargers and a related technology -- direct fuel injection -- on a large portion of its fleet in the near future, calling the move a “cornerstone of Ford’s near-term plan.”

The first Ford vehicle to get the boost will be the new Lincoln MKS, which will be introduced next spring with a standard engine but will go turbo by early 2009. The new engine will be smaller -- 3.5 liters versus 3.7 liters -- yet have better performance.

“This is not something on the drawing board. Turbos are here,” said Adriane Brown, president and chief executive of Honeywell Transportation Systems, the leading turbo manufacturer, with $2.5 billion in turbo sales last year. As turbos gain more acceptance, she expects sales to grow three times faster than the automotive segment in the next few years, or about 8%.

Turbos are hardly new. After finding a place on ships, locomotives and airplanes in the first half of the last century, they were adopted for passenger cars in the 1970s when BMW, Mercedes, Mitsubishi and even Buick bolted them on manifolds. Despite popularity among car tuners, they quickly lost acceptance among the general population, which saw them as unreliable, expensive and, with their sudden bursts of acceleration, dangerous.

Older turbos delivered great amounts of torque, yet frequently there was a short time gap between stepping on the pedal and feeling the power. That gap, called turbo lag, could cause unsuspecting drivers to crash.

New turbo technology has essentially eliminated that gap while providing variable boost depending on the engine velocity, turbo manufacturers say. And turbos add only slightly to the cost of a car, they say, between $1,000 and $3,000 -- part of which can be offset by using a smaller engine.

And though some carmakers are just now embracing the technology (and a very few still shun it), others have been pressing the turbo button for years. GM’s Saab, for example, has long used turbocharged engines and Subaru has had them in cars for 25 years, including four current models.

In Europe, turbocharger-equipped diesel engines are far and away the most common engine type, approaching 50% market penetration. Yet in the U.S., said Honeywell’s Brown, only 6% of cars and truck are “boosted.”

That gap, experts say, is largely due to American tastes -- and prejudices. Simply put, Americans want big, heavy motors, and they associate displacement (the volume of air and gas drawn in by an engine) with power. Turbos, on the other hand, are seen as accouterments for tin-can sports cars and low-slung street rodders, hardly something useful for towing, say, or even lugging children to soccer practice.

The reality, however, is that turbochargers have been on heavy-duty trucks in the U.S. for years; the Big Three automakers had 19 turbocharged diesel truck models in their 2007 lineups, according to edmunds.com.

“The U.S. is probably the last market to look at the upsides of downsized turbo engines,” said Mary Brevard, spokeswoman for supplier Borg Warner, which saw sales of its turbos increase 17% last year, to $825 million. “Americans think bigger is better, but if they drive a turbo, they find out it’s a [powerful, high-performing] car.”

They may be finding out, whether they like it or not. With government fuel consumption standards expected to rise significantly in the near future, many automakers see turbos as the cheapest and easiest short-term way to increase efficiency.

In July, a few months prior to revealing its experimental, 68-mpg hydrogen fuel-cell car at the L.A. Auto Show, Honda unveiled a clean diesel with a turbocharger that gets 63 mpg. Unlike the clean diesel, which could be on the market in no time, hydrogen cars cost as much as $1 million each and are at least a decade away, most experts say.

That kind of thinking is sinking in, even with the most conservative carmakers; that’s why analysts expect turbo penetration of the U.S. market to reach 15% by 2012.

“We’re looking at equipping very, very large cars with very small four-cylinder, turbocharged engines,” GM Vice Chairman Bob Lutz said, mentioning the Cadillac DTS and the soon-to-be available Pontiac G8, both of which have eight-cylinder motors.

The notion that a high-efficiency, carefully tuned four-cylinder could seamlessly replace the big-block monsters that have defined American roading for decades is practically blasphemy in some circles.

Yet for Jake Fisher, an engineer at Consumer Reports, it’s an unavoidable step. He describes being amazed driving a turbocharged BMW 535i, and even more so when he learned that it got three miles per gallon more than the nonturbo Infiniti M35.

“It has 300 horsepower and still gets 22 miles per gallon,” he says. “That’s what a turbo does.”

ken.bensinger@latimes.com