Powertrain for better performance

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Scania Group Press Release  /  September 21, 2016

In Scania’s new truck generation, the news under the cab floor are as impressive as that above it. With the innovative powertrain improvements, fuel consumption is further reduced by three percent, significantly contributing to the overall savings of five percent.

Changes include a reworked combustion chamber and new injectors. The generally higher working temperature and the fact that the oil cooling is thermostatic contribute to additional savings. The cooling fans – which in some cases have a greater diameter – are now directly driven without energy wasting upshifting. Thermostatic oil cooling saves fuel since the oil retains an optimum temperature, even at a lower power outlet and in low outdoor temperatures.

Moreover, Scania introduces a layshaft brake system as standard in automated Scania Opticruise gearboxes. Instead of, as in most conventional gearboxes, using synchro rings to synchronise the different speeds of the layshaft and main shaft in the gearbox during gearshifts, Scania uses a lay shaft brake when upshifting. This is possible thanks to Scania’s approach with fully integrated powertrains and means that the shafts synchronise with each other significantly faster and that the next pinion – i.e. the next gear – can engage almost immediately.

Thanks to the lay shaft brake, Scania’s most popular long-haul truck gearbox shifts up a gear in 0.4 seconds, nearly halving gearshift time. Not only is the actual gearshift time shorter but that also helps maintain turbo pressure. Therefore, the vehicle will upshift into the next gear with greater power, while feeling smoother than before. This feature will lead to both better handling when driving under tough conditions and better performance in all types of road driving, including the actual starting torque at take-off.

“This technology is hassle-free, and it makes a big difference in driving experience and performance,” says Magnus Mackaldener, Head of Transmission Development.

Minute news is big news

Imagine forcing a miniscule drop of .0004 litres of diesel with a pressure of 2,100 bar through ten holes of a fuel injector nozzle, each hole with a diameter of two-tenths of a millimetre or roughly 2–3 strands of human hair. That is precisely what the high pressure fuel injection system in Scania’s new truck generation does some 500–1,000 times per minute.

Increasing the injection rate combined with a greater flow helps to optimise combustion and thereby reduce fuel consumption. Despite the unbelievably minute dimensions, the system has been further improved to allow a greater liquid amount and more evenly distributed fuel spray into the cylinder.

“To reach optimal engine efficiency, while considering fuel consumption, our primary objective when designing the new fuel injector was to be able to provide the exact amount of injected fuel at a faster rate, whilst maintaining exceptional reliability and durability,” says Stephen Conway, Head of Fuel Injector Performance.

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