2 In 019 around 1000 experts in motor and drive technology came together in the Vienna Hofburg to discuss the perspectives of their subject. The 40th Motor Symposium seems to mark something like a turning point. In times of the “diesel scandal”, nitrogen oxide and fine dust levels in cities and, last but not least, a more intensive discussion about the limitation of CO2 emissions in the course of the Paris climate agreement, the focus in Vienna is also shifting significantly to emissions and CO2 emissions all in all. Even if the share of road traffic in Germany is only 18 percent, its CO2 emissions have increased by 28 percent since 1990, as Bosch boss Volkmar Denner quoted in his opening statement.
How is traffic going? CO2 neutral?
If the agreed goal of the Paris Agreement is to be achieved, the transport sector must become climate neutral by 2050. From this, he makes the short-term forecast that by 2030 every fourth new vehicle will be purely electric. At the same time, there will be strong electrification of the internal combustion engine with mild and strong forms of hybridization. However, this prognosis also means that the pure combustion engine will then keep a considerable share with a share of 40%. However, its great potential for improvement must be consistently exploited. Suppliers such as Continental, Delphi, Mahle or even Bosch will also make a decisive contribution. The Stuttgart specialist even wants to make its production climate-neutral through renewable self-supply and green electricity procurement by 2030.
Volvo is on a similar path, as its development board member Henrik Green explained in his article. By 2025, he expects that half of the new vehicles delivered will be fully electric. Until then, hybrids and plug-in hybrids should gradually pave the way. The next generation of a scalable platform should also be geared towards connectivity and safe autonomous driving with a three-part computer architecture.
Mild hybrid with 48 volts across the board
The path to hybridization - this has also been clearly shown by many other manufacturers in Vienna - is initially via have a 48-volt electrical system. The system based on this will be introduced in the eighth generation of Golf. A belt starter generator replaces the 12 V generator. This not only enables the combustion engine to be supported in consumption-intensive phases, but kinetic energy can also be recuperated in the 48 V lithium-ion battery during sailing phases. VW developer Michael Zillmer, with such a comparatively inexpensive, mild hybrid system, promises a consumption advantage of around 0.4 l /100 km.
Of course, the ID.3, the concept for pure electrification, too VW cars was a subject that was sometimes controversial. In particular, the proponents of traditional combustion engine technology, such as the former Opel and GM developer Fritz Indra, keep asking the question of a holistic energy and CO2 balance. And no, even the recently maligned diesel engine still has a future. With the third generation of its 3.0 l V6 TDI, Audi continues to rely on the diesel engine. What is new is that the previous biturbo is now being followed by a combination of a single-stage exhaust gas turbocharger and an electrically driven compressor. And that too is now relying on a 48 V system, admittedly more for reasons of driving dynamics and in preparation for real hybridization. Of course, this couldn't be done entirely without exhaust gas optimization, so that at least the EU 6d-temp emissions standard is complied with.
Even Hyundai still relies on diesel
Even in Asia you can still see diesel engines for them a good future. Hyundai developer Jerok Chun presented the new development of a 2.2 liter four-cylinder diesel that will replace the previous R engine series next year in order to achieve the Euro 6d emission standards. The cornerstones of the new concept are an injection pressure increased to 2,200 bar, a water-cooled charge air cooler and exhaust gas recirculation divided into high and low pressure.
Which drive type is low in CO2 overall?
In view of the diversity of technology and the hype surrounding e-mobility, however, the question arises again and again of how a holistically considered carbon footprint becomes possible in the drive of the future. Mahle researcher Otmar Scharrer is looking for answers in a project that investigated synthetically produced fuels for internal combustion engines - and especially for the existing fleet. Provided that a synthesis with the help of regenerative energies is possible on a large industrial scale, the results are thoroughly encouraging. A five percent admixture of dimethyl carbonate (DMC) would be a promising first step due to its high knock resistance and high calorific value of the mixture. The CO2 saving potential could be increased with an increasing degree of mixing, but would be problematic in temperatures below zero because of the low temperature properties of DMC. Tests in a Porsche six-cylinder have shown the practicality very convincingly.
In another project 'XME-Diesel' funded by the Federal Ministry for Economic Affairs and Energy, sustainable, synthetic fuel alternatives for the compression-ignition engine were systematically investigated Ford researcher Werner Willems presented. Dimethyl ether (DME) in particular turned out to be a promising replacement candidate for fossil diesel fuel. After necessary modifications to the injection system, a Mondeo-based demonstrator showed low fuel savings and, above all, soot-free combustion including a 33% reduction in NOx.
Is the combustion engine sustainable?
It could therefore be possible to ensure the future viability of the internal combustion engine with alternative and synthetic fuels. Of course, publisher Wolfang Maus is also convinced of this when he presented his new book “Future Fuels” at the Vienna Motor Symposium. In the almost thousand-page tome, many other fuels are included in a future energy transition. The only questions that remain open at the moment are their costs and where we want to get CO2-free energy from. 'There is enough energy', Maus is convinced, 'we only need targeted political decisions.'