Higher Gas-Mileage Rules Give Turbos a Big Boost

(MoneyWatch)  If you like turbochargers, you'll love the next five years.

More automakers are adopting turbos as a way to achieve tougher fuel efficiency targets, because a more fuel-efficient, turbocharged four-cylinder engine can produce the same power as a thirstier six-cylinder engine without a turbo.

Honeywell Transportation Systems, a leading manufacturer of turbochargers, says half of the new cars sold in Europe today are turbocharged, including diesels, and that share could rise as high as 75 percent in the next five years.

The U.S. market is following the same trend, from less than 5 percent turbos today to around 20 to 25 percent in the next five years, according to David Paja, marketing vice president of Honeywell Turbo Technologies. In the long run, the North American market could potentially match the European market, he said.

"We are coming to a point where all things are converging," Paja said in a phone interview today.

U.S. consumers are getting more interested in fuel efficiency. At the same time, the U.S. government is adopting much tougher standards for Corporate Average Fuel Economy. Meanwhile, due to improved materials and design, the latest generation of turbochargers is more fuel-efficient and reliable, he said.

Separately, in a presentation yesterday at the Columbia University Business School in New York, Massachusetts Institute of Technology Professor Daniel Roos said that by 2035, turbocharged gasoline engines could grow to 25 percent of new-car sales, plus another 15 percent diesels. Those would likely be turbocharged as well.

Ford is a leading proponent of turbocharging, combined with direct-injection gasoline engines, a combination Ford calls EcoBoost, to achieve what Honeywell calls "transparent downsizing" of engines. Honeywell is a Ford supplier, along with other global car makers.

Transparency means a turbo four-cylinder engine can perform like a six, except in fuel consumption. Similarly, a six-cylinder engine can substitute for an eight-cylinder. What's "transparent" is that the customer shouldn't feel any sacrifice, except better fuel economy.

That transparency also depends on improvements to the turbochargers themselves. The knock on turbochargers of 20 years ago was that they increased fuel consumption for the same size engine, and were more prone to failure, due to high heat and high-speed operation. Turbochargers get so hot in normal operation they can literally glow red-hot.

Earlier turbochargers were also more prone to "turbo lag," where there's a time lag between stepping on the accelerator and feeling the additional power.

The latest turbochargers can all but eliminate turbo lag; they're more fuel-efficient, last longer, and operate at even higher speeds, for instance up to 200,000 rpm, Paja said. That's spinning at a rate about 100 times faster than the rest of the car's engine normally operates.

There's still a fuel-economy penalty for adding a turbo to the same-size engine, but it's a smaller penalty than before -- and again, today's philosophy is to turbocharge a smaller-size engine to achieve better gas mileage, rather than add a turbo to the same-size engine for more power.

Rather than an exotic add-on, "We are getting close to the point where a turbo is an integral part of an engine," Paja said.

Graphic: Honeywell