Turbochargers can boost power on demand within a certain range of speeds.
How it works
Exhaust gases are recycled and forced through a turbine, causing it to rotate. This draws in air from the outside, which is cooled and forced into the engine cylinders. The extra air creates more powerful and efficient combustion. This in turn boosts economy and performance, and cuts emissions. Variable geometry turbochargers have adjustable vanes that allow the turbocharger to provide more boost at lower engine rpms without producing too much boost at higher speeds.
Where to find it
Turbochargers are on most diesel models sold in Europe and the United States. Because diesels represent about half of the new-car sales in Europe, the region will account for about 70 percent of worldwide turbocharger demand this year -- or between 8 million and 9.7 million units.
The high exhaust temperature and range of operating speeds in a gasoline engine are more demanding than in diesel engines. The maximum temperature of a diesel's exhaust is about 1,472 degrees Fahrenheit; gasoline engines can run as high as 1,832 F. As a result, it costs too much to make the movable turbine blades durable enough to withstand the heat in direct-injection gasoline engines.
Mitsubishi Heavy Industries, BorgWarner Inc. and Honeywell International.