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  Trucks (in general) - 4



No, today's utility vehicles really do have enough performance. As far as some haulage operators are concerned, they even have too much, in view of the V8 engines, they're worried about keeping the consumption to within limits. Thus, not only in Europe, but basically all over the world, they have settled for the in-line six-cylinder. Even Mercedes has, in the meantime, given up their special role and abandoned their V6. Many countries are not in any position to defend themselves against certain technological developments, the European manufacturers have also in these places, a market-controlling position, e.g., in North America. It will be interesting to see, if such an economic purging will take place in the motor car field with the four cylinder in-line engine.

In earlier times this was different. Rudolf Diesel's engine, which because of its high effectivity and the possibility to use more economic fuels, was actually thought of as a replacement for the petrol engine, it was only laboriously realized during his own lifetime, and even then in fact, was a Herculean task. Diesel himself never lived to see how, from the ship- and locomotive power unit, in 1923, a truck- and 13 years later, also a motor car engine came to be. Indeed, even then its construction-type was by no means a certainty.

Already the Benz and Daimler-Diesel engines had two different secondary combustion chamber processes, while MAN injected directly. In the 1950's MAN even tried out the M-process (recessed-head piston). In the meantime, Krupp e.g., favoured the two-stroke, nowadays reserved for only the very largest ships Diesels. Any imaginable type of engine can now be found, from the in-line- or V-shaped 8 (or more) cylinder, up to the double-six, as a petrol- or a Diesel version, air- or liquid cooled, front mounted or as an under-floor version. The direct-injection common to them all nowadays, appeared around the end of the 1960's, indeed not without a great deal of labour-pains in the shape of engine damages.

Even though the classification up to Euro-6 is not comparable with the pollutant limits for the motor car, by the way, neither are Diesel and petrol cars either, a great deal has still been achieved. The fuel consumption has been reduced, despite the further increase in performance and the improved exhaust gas values, in the latest stage however, only by substituting the saved fuel with Adblue, which is also a good bit cheaper. This is thanks to the charging and the increased injection-, charging and medium pressures. Whether the displacement will be reduced with the rising charging pressure (downsizing), is not yet foreseeable.

One should not forget about the gearboxes, which can help to exploit the torque better, and this has been increased even more than the performance. The gearboxes with at most, five speeds in buses, now have eight speeds. The option of doubling this amount is no longer reserved for construction site vehicles, it is also helpful for 40-tonners when driving uphill on the motorways. The low-limit RPMs in vehicles like this can hardly be further reduced. There are already rumours of achieving a consumption of 20 liters per 100 kms with certain test horse-and-trailer vehicles. In reality, this is, depending on the load, still 30 to 35 liters.

Also the extremely gnarly gear-changing is really a thing of the past. If not fully automatic and sequential, at least the clutch pedal can be folded out of the way. The era of the four shifting-gates for the forward gears is over. In North America some drivers of older vehicles still have to battle with an unsynchronised gearbox, the necessary technology however, is in principle at least, also available there. Relatively new are the technologies, e.g., special converters, which reduce the enormous amount of effort that the clutch has to cope with when pulling off, at the same time, wear and tear is avoided.




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