Turbochargers take exhaust pressure and convert it to intake pressure. The normally work on a ratio of about 2:1, where 2 pounds of back pressure (exhaust press

Turbochargers take exhaust pressure and convert it to intake pressure. The normally work on a ratio of about 2:1, where 2 pounds of back pressure (exhaust pressure) is converted to 1 pound of intake pressure. Since this pressure(and gas expansion) is normally wasted (except in aircraft where it can be used to propel the craft forward) it is a consider more efficient than supercharged setup.