For a long time they were only built as inline and V engines. Recently, they are even available as flat engines (Subaru). They appear almost only with supercharging, seem to be almost intermarried with the turbocharger. The compressor or the turbo-compound system is less common. If, as with stationary engines, an optimum is to be found in many operating ranges, mechanical control systems can still be used today.

The development of the diesel engine in a passenger car is even more incredible than in the truck. In the last fifty years small Diesel engines have developed from low-power roughnecks to cultivated engines, which are equipped with a lot of boost also from lower speeds. In the meantime, they have even been seriously competitive with long-distance racing.

While the nominal speed of the commercial petrol engine is rather declining, the speed of the Diesel has in the first transition period of direct injecting and now increased again. Depending on the manufacturer, it is possible to achieve speeds of up to 5500 rpm. The Diesel engine seems to have any maximum or minimum size. For example it is even wellknown in the shipbuilding industry, but now also appears as a three cylinder with less than 1000 cm³.

Since it is now only used as a direct injection as well as in trucks as in passenger cars, it is almost unbeatable in its efficiency. And its torque has grown a lot since the introduction of the turbocharger, that it had to be limited artificially by itself with regard to the available transmissions. In the beginning, with such strong engines only converter automatics were used. The engine appears to many manufacturers now also as for coupés and even convertibles suitable.

But there are still possibilities of conquest for the diesel engine. In the USA, the average consumer still fights violently, although he seems particularly suited to large and heavy vehicles. Gas has been favored there since time immemorial, although its price, at least in the interim before the fracking began to lead to a partly solution of the lack of resources.

The North American have kept the diesel engine for passenger cars from their market for a long time because they have strictly demanded the same exhaust gas values as for the petrol engine, e.g. for the oxides of nitrogen. In the meantime, the Diesel seemed to have taken this high hurdle in Europe and North American market, too The Diesel scandal put an preliminary end on this development.

You may have noticed the Diesel catched up to the gasoline engine in the exhaust gas collection system. Even if the gasoline is more often injected directly, it can not quite reach the low diesel consumption. There is still an advantage for him, that is the running cost question. With the weight of the vehicles as far as the utility vehicle area, however, the dominance of the diesel engine increases, too, even In the United States.

We should not forget to mention the areas of agricultural and construction machinery, locomotives and ships, the latter having already caused a sensation shortly after the invention of the diesel engine. Today, the largest container ships in the world reach with it up to 74,000 kW (100,000 HP) efficiencies of well over 40 percent. Additionally, they are driving a bit slower to save fuel.

Because this is about a very accurate cost calculation. If you think that 1 liter of crude oil is transported around half the globe for about 2 cents, you may be able to feel the bottom-line calculation. Unfortunately, however, a kind of heavy fuel is also burned on the open sea, which can only be burned in the engine when it has previously been heated up to 160°C, so not very environmentally friendly.

Yeah, the environment. At first glance, the Diesel engine seems to depend exclusively on fossil fuels. This is not the case, however, there are already sufficient possibilities to supply it with products of renewable raw materials. The rapeseed which is easily prone to monocultures is more likely to be attributed to biodiesel 1. Scientists have rather the residuals of agriculture or forestry or e.g. also rapidly growing algae structures.

That would be good with the further development of the diesel engine. One would have liked to go further. For example a more sulfur reduced fuel, may be at all a synthetically produced, one precisely tailored to the requirements of the Diesel engine. And if you do not distill it from petroleum anyway, you can also prepare it artificially. 'Sunfuel' is the name of the product, which is still slumbering in laboratories and promises a further development thrust on the diesel engine.

How difficult the development of diesel engines, is shown in the following calculation examples. Suppose a diesel engine consumes 1 liter of fuel per hour at idle. This would then be 1,000 cm³ and 1,000,000 mm³, respectively. Then this is 250,000 mm³ for each cylinder. Makes up 4.167 mm³. per minute If we start from 800 revolutions per minute, we have to divide by the four-stroke principle by 400, because only every second revolution is injected.

Thus, approximately 10 mm³ are obtained in each injection process. If you consider that this corresponds to a cube with just 2.2 millimeters of edge length and rain drops have a volume of about 30 mm³, then that is very little. There are Diesel engines that can do with even less injection quantity and of which 20 percent pre-injection.

At full load, the diesel engine is by no means economical, can even more consume than a gasoline engine with the same power. If we accept 18 liters per 100 kilometers, we have by no means a particularly large engine in mind. In a big SUV at full load It could also be a four-cylinder.

Here, too, we can divide by 4 and arrive at 4.500.000 mm³, which would have to be distributed to 30 minutes at an assumed speed of 200 km/h. At 4,500 rpm we would have to divide by 2,250 and get a good 60 mm³ for each injection process. It could spread to 5 parts injections.

4,500 rpm correspond to 75 injections per second. 27,000 degrees crank angles are thus returned, ie 27.degrees. Per millisecond. If we take a pre-injection and a post-injection, then 3 of the 5 parts injections should already be placed somewhere in the first 60° crank angle. The motor management then has to open and close the respective injector three times each time in about 2 milliseconds, in order to inject about half the volume of half a drop of the syringe under a pressure of more than 2,000 bar.

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