A Mix of Powertrain Options Seen as the Ideal Solution for Clean Mobility

Author: Thomas Schneider

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At the opening, Dr. Johannes Liebl, Scientific Director of the Conference, emphasises “honesty with politicians and environmental associations about the technologies”. This assessment runs like a thread through the three keynote speeches of Professor Christian Schwarz (BMW), Dr. Otmar Scharrer (Mahle) and Dr. Markus Schwaderlapp (Deutz). Achieving what is technically and economically feasible is also important, but this also requires further optimisation of internal combustion engines. Participants also agree that CO₂-neutral synthetic fuels can greatly contribute to achieving current and future limits.

In his speech “Mastering the Future of Gasoline Engines”, Professor Schwarz predicts that the 95-gram CO₂/km target appears achievable with further improvements in efficiency. Efficiency can be increased through cylinder deactivation, exhaust gas recirculation and variable compression. “The conventional internal combustion engine has the potential to reduce CO₂ emissions by another ten percent at an acceptable cost, but further improvement is becoming ever harder to achieve.” Other options include water injection, electrically assisted turbochargers and recuperation. The current electricity mix means that conventional internal combustion engines are clearly superior to battery-electric vehicles in terms of CO₂ emissions, especially when using carbon-neutral synthetic fuels, which can largely solve the CO₂ problem.

The internal combustion engine continues to be optimised

In his keynote speech “Powertrain 2030: Driven by Diversification”, Dr. Otmar Scharrer from Mahle illustrates how crucial further improvement of the conventional internal combustion engine still is. It will continue to dominate and will account for 75 percent of cars around the world in 2030 even with growing e-mobility. Apart from electrification, his solution is also to use alternative fuels with which “we can double savings”. These fuels must be offered in liquid form wherever possible and standardised. The effect is huge: “One percent of renewable fuel offers the same savings potential as ten million electric cars,” says Scharrer. Renewable natural gas, which can also be used to store surplus energy, is the preferred choice in this case.

In his lecture “Towards CO₂-neutral Mobility in Off-highway Applications”, Dr. Markus Schwaderlapp explains that powertrain electrification has also reached the construction machinery sector, with 48-volt hybrid drives and also 400-volt plug-in hybrids both being in development and making a contribution. However, electrification and particularly battery-electric powertrains are not possible in every field; simply switching to an electric drive is impossible for heavy-duty machines and those in continuous operation. 

Liquefied petroleum gas-fuelled engines are far more practical, and the new Euro 5 emissions legislation will also make them more economically viable. In future, Deutz will increasingly rely on multifuel engines. As a necessary second approach besides electrification, Dr. Schwaderlapp also emphasises in this respect the importance of renewable fuels, which now require rapid and thorough development and propagation.