ABSTRACT
Drive trains for passenger cars are changing rapidly as the market moves away from diesel towards hybrid gasoline/electric, battery electric and hydrogen fuel cells. This will have implications for turbocharging that are only starting to become evident. Hybrid cars and electric cars with range extender ICEs will still offer opportunities for turbocharging. The use of an electric machine can reduce the low speed torque requirements of the ICE and the turbocharger can be re-optimised to emphasise efficiency over range and inertia. The benefits will vary with individual circumstances, but in the most favourable conditions it might be as much as 5-7 percentage points for the compressor and turbine efficiencies.
There is good evidence that battery electric and fuel cell vehicles are less favourable to CO2 emissions than hybrid vehicles in the short and medium term, but the final decision will be based on geopolitical and market factors rather than technical evidence. Such a switch will create opportunities for air cycle machines and electrically-driven compressors based on turbocharger technology, but in market terms these are unlikely to compensate for the loss of the passenger car turbocharger market.
