The internal combustion engine is dead. It has a long life internal combustion engine. The European Union has decided to put an end to internal mobility or at least block sales of diesel and gasoline cars, but also hybrids and plug-in hybrids starting in 2035. The opposition to the German measure managed to do so. Internal combustion fuel has at least a chance to continue in new passenger cars registered beyond 2035, along with a new generation of synthetic fuels and biofuels that are neutral.
There is a lot of discussion these days about neutral internal combustion. And we believe that it is a good time to remember some of the best stories that are with original, surprising and innovative internal combustion engines, and this even in some cases like this, in which they did not reach production, the technology had your site at dealerships.
Today we go back to 2007, to see the engine under the hood of Mercedes-Benz technological shows.
The work of engineers in internal combustion engines has left us marvels of craftsmanship that in many cases have not been reached, nor will production ever reach.
A wonderful gasoline engine “without spark plugs” from Mercedes
Getting a gasoline engine with compression ignition, without spark plugs, and with a combustion process very similar to diesel, is like a utopia that many manufacturers have been chasing for some time. In recent years, we have seen how Mazda is going to approach that approach through a gasoline engine with compression ignition, typical diesel. But, as we said, there are not a few manufacturers who have been making machines with this philosophy for decades.
16 years ago Mercedes-Benz at DIESOTTO, one of the richest Mercedes-Benz developments, offered us a strategy that we would never see applied to a street product, in a production car. And a design that, like most of what has been developed for perfect internal combustion, awakens our most nostalgic humor in us, at a time when the brands were directed only and only in the electric car, with the exception of neutral synthetic fuel. that the European Union will also consider a valid option beyond 2035.
And what engine Mercedes-Benz DIESOTTO? Why have we never seen it in traffic?
Mercedes-Benz DIESOTTO made the engine without spark plugs, managed to control the combustion of gasoline with the ignition on the compression engine, just like on the diesel engine
The “utopia” of a gasoline engine with compression ignition
The reason why it is so interesting to work with a gasoline engine with compression ignition is that it is very effective in researching the combustion process. Everything is convenient. If we complete the combustion process, we will achieve extraordinary efficiency for a gasoline engine, closer to what is achieved by a diesel engine. If we do without diesel and achieve it with a gasoline engine, we also make a cleaner combustion and free from some of the most problematic substances from the combustion of diesel, such as the harmful NOx, which has generated so many pollution problems in many people. cities Europe.
We are talking about a very complex and expensive technology, which at one time was considered necessary and interesting as an alternative to diesel, which, to reduce its emissions, also relied on complex and expensive solutions, such as exhaust gas sequences.
While internal combustion engines had a future, manufacturers were looking for a more efficient combustion process.
Del motor DIESOTTO al F700 Concept
We stopped beating around the bush for miles to remember the DIESOTTO engine. Mercedes-Benz pioneered this technology in a prototype in 2007 as the Mercedes-Benz F700 Concept. From his name we can already imagine that he was not a front model, he stopped at the car show, attracted lightning and took a photo. That prototype was actually an experimental model. Since those C111s in the sixties and seventies, Mercedes-Benz has created a long list of fully functional prototypes to research future technologies. Prototypes that were tested to fatigue to create better street cars.
Although Diesotto’s engine technology was already quite promising, Mercedes-Benz opted for a combination of a gasoline turbo engine associated with a hybrid system, with a small 15 kW (20 HP) electric motor support. Under this combination, Mercedes-Benz has managed to create a huge litter machine, as long as the Mercedes S-Class – produced with a V6 engine, with nearly 260 HP of power, and a consumption (according to the old NEDC cycle) of 5.3 liters. / 100 kilometers.
If we focus on DIESOTTO and forget about the hybridization of this prototype, we would find a four-cylinder gasoline engine, 238 CV of power and a proven consumption of less than 6 liters/100 kilometers in a vehicle the size of a Mercedes-Benz similar to what can be tested today by the most severe Mercedes S-Class Diesel.
Through hybridization, the Diesotto engine could achieve consumption – according to NEDC approval – of 5.3 litres/100 kilometers in a vehicle the size of the S-Class.
Compression ignition and variable compression
With DIESOTTO, Mercedes-Benz has created a true technological adventure. Not only because of the pressure to achieve the ignition process, but also for betting on other very promising technologies. That engine features a turbocharger, variable valve lift control, and variable compression. Mercedes-Benz switched to a compression system that modifies the compression ratio of the pistons, using a system very similar to the Lanchester axles.
We have to put a lot of words when it comes to homogeneous lean mixture and compression ignition. Because it was another thing for DIESOTTI. The Mercedes-Benz engine had hybrid ignition management, so that in conditions of maximum load for the eng
ine, ignition was made by spark plugs. Meanwhile, at low and medium engine loads, the fuel-air mixture is ignited by compression. The idea that Mazda would use in its SKYACTIV-X would again be similar to the one that Mercedes-Benz developed for the technology show in 2007.
This dual mode of operation, together with variable compression ratios, has made the DiesOTTO engine, offering excellent performance and unique efficiency for an engine of these brands.
In addition to compression ignition, Diesotto had a system of varying the piston stroke and therefore the compression ratio.
At that time, Mercedes-Benz promised to introduce these technologies to its passenger car in the mid-term. But to date we have not seen a production Mercedes-Benz equipped with Diesotto equipment and, unfortunately, we never will (we are now totally convinced).
And the reason why Mercedes-Benz Diesotto, obviously, has not opted for new engines, is always the same. We are talking about the feasibility of the issue. Such a complex and particular device, in addition to having credibility, proves to pass with flying colors, which is not so easy when the number of parts increases, more prone to fail in one way or another, and the operational logic is complicated. to be financially viable. If not, Mercedes-Benz could either continue what they did with their diesel or improve the technology of their gasoline engines. It should be noted that Mercedes-Benz has significantly improved the catalog of gasoline engines, especially four-cylinder, direct injection and turbo.
At the moment, unfortunately, there is no longer room in large developments to excite internal combustion and projects such as this one, with a few and honorable exceptions, such as the aforementioned Mazda engines, or ultra-exclusive and exotic projects such as Mercedes-. AMG One
