Because it has to be cheap and reliable at 1000*C for 200,000 miles over 10 years while constantly accelerating to 280,000RPM and decelerating with no oil or co

Because it has to be cheap and reliable at 1000*C for 200,000 miles over 10 years while constantly accelerating to 280,000RPM and decelerating with no oil or cooling air circulating when the car is stopped. https://garrett.honeywell.com/products/how-a-turbo-works/ https://garrett.honeywell.com/products/how-a-turbo-works/ http://www.epi-eng.com/piston_engine_technology/turbocharger_technology.htm http://www.epi-eng.com/piston_engine_technology/turbocharger...