The Future of Gasoline Engines

Authors

Dr.-Ing. H. Zhang, Dr.-Ing. E. Achleitner,
Dipl.-Phys. J. Beer, Dipl.-Ing. F. Kapphan,
Dipl.-Ing. W. Klügl, Dr.-Ing. O. Maiwald,
Dr.-Ing. G. Rösel, Dr.-Ing. J. Ehrhard,
Continental, Regensburg/Grünstadt

Year

2015

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 783

Summary

Gasoline engines - both direct and port injection - are and will remain the most widely used powertrain solution for individual road vehicles for the next decades. The task of engineers is to meet drivability and performance requirements within the legal framework of more stringent emissions legislation and CO₂ reduction of vehicle fleets. New test procedures such as the WLTP (Worldwide Harmonized Light Duty Driving Test Procedure) and compliance with the emissions in real driving conditions raise the hurdle even higher. This report examines current development activities to achieve the above objectives. To fulfill future CO₂ targets a combination of improved thermodynamic efficiency of the internal combustion engine and the right degree of powertrain hybridization are mandatory. The presented engine efficiency technologies are charge dilution by air and cooled exhaust gas (EGR), a Miller cycle valvetrain strategy and the combination of both. The Miller cycle is used as an example to show that advanced charging technology can compensate for the negative impact of Miller specific valvetrain strategies on the transient behavior of the engine. Due to the global trend toward larger cars, the hybridization of gasoline vehicles becomes more important to achieve the vehicle manufacturer's fleet fuel economy goals.