«Der Diesel war schon immer sehr sparsam, jetzt ist er auch noch absolut sauber.» Sebastian Willmann, Leiter Dieselmotoren-Entwicklung bei #volkswagen über die Zukunft des Dieselmotors. Das ganze Interview gibt es hier: https://blog.volkswagen.ch/technik-i...tian-willmann/
"The diesel has always been very economical and now it is absolutely clean." Sebastian Willmann, Head of Diesel Engine Development at #volkswagen on the future of the diesel engine. The whole interview is here:
With the 2.0 TDI EA288 Evo, Volkswagen is introducing a new generation of diesel engines that significantly undercut the limit values of the current Euro 6d-Temp standard. Sebastian Willmann, Head of Diesel Engine Development at VW, on the hurdles a new engine needs to take and the future of the auto-ignition.
Mr. Willmann, how does one proceed as an engineer in the development of a new engine like the diesel engine EA288 Evo?
First of all, there is a requirement in the room to fulfill customer wishes and legal requirements. The task is to develop a marketable product within the scope of the statutory emission requirements. Of course, the costs are also an important criterion here. The diesel engine is very popular with customers because of its longevity, often with mileages of between 400,000 and 500,000 kilometers. The robustness is therefore given special consideration in the concept definition.
How long have you been working at this stage of development?
The development process of engines at Volkswagen goes on for several years and starts with the pre-development phase, which is followed by series development. At the end there will be the validation and the series approval.
What hurdles must a new engine take until it is ready for production?
The legal as well as the technical requirements must be fulfilled. The emissions are a focal point. With the introduction of RDE legislation (Real Driving Emissions), securing emissions in practice is a complex challenge. In addition, our engines are tested in challenging endurance periods of more than 1000 hours on the test bench and driving tests of more than 100,000 kilometers under more stringent conditions. Only then does an aggregate receive series approval.
"The diesel has always been very economical, now it is absolutely clean."
What was the goal in the development of the new diesel engine?
Originally, the concept was set up to further reduce CO2 emissions and therefore also consumption. In the course of the development, however, the exhaust gas legislation has evolved, so that further technology components, such as the dual SCR system (see box), have been decided. Additional points such as the improvement of comfort and driving dynamics were also included in the specifications.
The EA288 Evo is first used by Volkswagen in the Passat. Which models are also equipped with it?
Shortly after the Passat follows the new Golf. Afterwards, the engine in the vehicles of the Modular Transverse Carrier will be successively introduced in three power levels with up to 200 hp.
How is the comparison to the popular predecessor engine?
We were able to reduce consumption by up to 10 g CO2 / km or about 0.4 l / 100 km compared to the already very efficient predecessor engine - and still increase its output. This is a significant step forward while reducing emissions.
Now, many manufacturers have distanced themselves from the diesel engine or even goodbye. Do you think that he still has a future?
The diesel will continue to be part of the drive solution for the VW brand in the future. He has always been very thrifty, now he is also absolutely clean. Vehicles with the latest emission technology, such as our current diesel engines, emit only very low nitrogen oxide emissions. Our models are at the level of the best competitors. Also, the comparison with gasoline engines, the new diesel no longer need to shy. Especially in heavier vehicles, where large ranges and a lot of torque are required and possibly even a trailer to be pulled, the diesel is still the most efficient drive today.
Significantly below the nitrogen oxide limit
In order to adapt the new four-cylinder EA288 Evo diesel engine to the very low emission limits of the Euro-6d-Temp standard, the raw emissions were reduced by various measures such as increasing the injection pressure. In addition, the exhaust aftertreatment system has been further developed. Sebastian Willmann explains: "In the passenger car sector, Volkswagen is using the double SCR system in the Passat for the first time. This allows us to meter the Adblue specifically before the two SCR catalysts. Compared to a simple SCR metering, the NOx emissions are further lowered while driving, with a tendency for lower Adblue consumption. Our Evo engine is well below the EU6 limit of 80 milligrams per kilometer on RDE cruises. »
1 High efficiency, low consumption
With a thermal efficiency of over 40 percent, the diesel is more efficient than the gasoline engine - and the CO2 emissions of the auto-ignition is correspondingly lower. It works with compression ignition, ie without spark plug, and therefore requires a higher compression. This also contributes to the increase in efficiency as the turbocharging. In addition, no throttle valve is required for power control, which largely avoids corresponding losses. Also important for the high efficiency is the diesel fuel itself: it contains more carbon per liter than gasoline.
2 Big range
The consumption of a diesel car is about 20 percent lower than that of a comparable gasoline engine. Thus, the diesel vehicle often runs with a tank filling more than 1000 kilometers. This is a very welcome time and comfort gain, especially for frequent travelers. Since high torques are available even at low speeds, the diesel can be operated very low-revolutions - which is good for consumption and smoothness.
3 clean exhaust gases
As a matter of principle, diesel combustion produces a higher proportion of pollutants than in gasoline engines - which mainly affects particulate matter and nitrogen oxides (NOx). However, these components can be effectively reduced thanks to the use of state-of-the-art technologies such as exhaust gas recirculation, oxidation catalytic converter, particulate filter and NOx storage catalytic converter. Volkswagen also uses urea injection systems (SCR) to meet the Euro 6d standards without any problems. In this case, a water-urea solution (Adblue) is injected into the exhaust line. The resulting ammonia converts the nitrogen oxides into water and non-toxic nitrogen.
4 Low fuel costs
The under-consumption of about 20 percent compared to a petrol engine leads to lower fuel costs - even in Switzerland, where the diesel fuel costs around five percent more than gasoline. For frequent travelers, the diesel is therefore the less expensive drive variant. In various European countries - such as Germany, France and Italy - the liter price for diesel is five to fifteen percent lower than that for gasoline, which further reduces the price per kilometer abroad.