In a turbocharger the impeller handles fuel-air mixture: true or false?

• A. True
• B. False
• C. It depends on the engine design
• D. Not applicable to turbochargers

Answer: (B)

It’s false. In a turbocharger, the impeller is part of the compressor side and is responsible only for drawing in and compressing clean intake air for the engine. It does not handle fuel or the fuel-air mixture. Fuel is metered by the engine’s fuel system and injected into the intake manifold or cylinders after the air has been drawn in and compressed by the turbocharger. The turbocharger has two separate fluid paths—the compressor handles air, the turbine is driven by exhaust gas—plus lubrication oil inside the housing, but fuel never passes through the impeller.