The end of 2010 sees another technical and environmental milestone for the trucking industry with the introduction of ADR 80/03. All new trucks over 4.5 tonnes being sold on the Australian market will have to meet stricter exhaust emission rules. They will need to be compliant with Euro 5, US EPA 07 or the Japanese New long Term 2005 regulations.
While these changes will not force manufacturers to make the kind of wholesale changes necessary with the introduction of ADR 80/02, this will be an opportunity to introduce new more sophisticated technology on many of the trucks on Australian roads. Scania is taking the opportunity to introduce an all-new 13 litre engine with a market leading fuel injection system.
The Swedish truck manufacturer is also taking the opportunity to introduce another technological innovation on its trucks – Scania has decided to bring its product offering a little more into line with its nearest competitors and introduce a two pedal automated transmission. The latest iteration of the Opticruise automated manual transmission is now available with an all new software package.
Scania has developed its strong reputation in Europe on the basis of its constant innovation and development of new technology in its trucks. In global terms, the company is a much smaller entity than many of the competitors (eg. the Daimler group, Volvo/Mack/Renault and the Paccar organisation). This reduces therefore its ability to spread the cost of expensive research across a large number of brands and models. Instead, Scania needs to be frugal with the limited research and development spending that is available.
XPI fuel injection
The development of the new XPI fuel injection system has been part of a long-term joint venture with another independent manufacturer, Cummins. The two companies had previously worked together on a unit injector for both Scania and Cummins engines and this latest development represents a major investment by both companies to come up with a sophisticated injection system to take its engines through the coming decade.
Cummins will be including this new XPI technology on its new engines for the US market at the end of this year and it is likely to be included in Cummins’ product in Australian trucks sometime in the next few years. The system is to be used on the new ISX engine compliant with the US EPA 2010 exhaust emission laws.
The new DC 13 engine will be available in the P Series, the new G Series and the R Series in four separate configurations, 360 hp, 400 hp, 440 hp and 480 hp. These engines will produce 1850 Nm, 2100 Nm, 2300 Nm and 2500 Nm of torque, respectively, from 1000 to 1300 rpm.
The new XPI system combines a number of advanced fuel injection techniques all in one system. As well as maintaining extremely high fuel pressure in a common rail at 2400 bar, the system also uses electronic fuel injectors to provide multiple injections on each combustion cycle. The combination of these two technologies means the combustion event can be carefully controlled with very precise and perfectly timed injection events. This has been optimised to produce the lowest exhaust emission levels possible.
Exhaust gas recirculation
The DC 13 also uses an exhaust gas recirculation (EGR) to get the levels of both nitrogen oxides and particulate matter down to the levels required by the regulations to be introduced on January 1, 2011. The whole process is aided by the inclusion of the Scania Variable Geometry Turbocharger (VGT). This maintains a high level of turbo boost throughout the rpm range enabling the fuel injection system and the EGR to do its job. Although branded as Scania, this technology is also sourced from Cummins subsidiary Holset.
With a maximum peak pressure of 2400 bar averaging out at 1800, this ultrahigh injection pressure system is running at higher pressures than those used by any other current truck manufacturer on the Australian market. A high level of computerised electronic control constantly monitors the engine’s performance, minutely adjusting the three injection event for each cycle.
“The flexibility of the 13 litre engine range means that it is just as much at home in a Scania P Series rigid truck used for local distribution, a Scania G Series construction truck or a long-distance prime mover equipped R Series,” says Scania Australia, Roger McCarthy. “We believe the new 13 litre lower emission EGR engine will provide the perfect solution in meeting our customers’ requirements. In addition, the 13 litre platform is perfectly matched to the new generation Scania Opticruise automated gearchange system, available in fully automated, or three pedal mode, bringing even greater control and comfort to the Scania driving experience.”
Scania’s Opticruise was one of the earliest automated manual transmissions on the market. The company had chosen to go down a different technology development path than many of its European rivals by basing its system on the same gearbox, with synchros, as it was using on its conventional manual drivelines. Other manufacturers went with a constant mesh gearbox with electronic clutch actuation.
The Opticruise system was developed without recourse to clutch actuation between gears. This had the effect of making early versions a little slower than its constant mesh rivals but by the time the second-generation automated manual transmissions were on the market, the Scania version was performing as well as its rivals. Throughout this development, the company retained the use of the clutch pedal to be used in slow-moving and in emergency situations.
Transmission enhancement
In 2010, Scania is introducing its first two pedal automated manual transmission with a radically modernised gear changing system and much improved control software for the transmission. Much of this improved performance will also be available on the three pedal versions which are to be retained when fitted behind the V8 engines and will be available as an option on trucks powered with the new DC 13 engine.
On all Opticruise options the new software will enable more intuitive gear selection picking up cues from an improved sensor in the accelerator. The system will not only monitor pedal position but will also measure the speed of pedal movement. This will help the gearbox understand the urgency of the request from the driver’s right foot.
On the two pedal version, to be called Fully Automated, further innovations have been included. On this version the clutch will be actuated electrically on each gear change. The system also includes much more precise speed control with a maneuvering mode available for reversing and the lower forward gears. An inclinometer is also now fitted on the gearbox to enable it to make more precise gear choices appropriate to the road conditions the truck faces.
The improved clutch response is made possible by the use of an electric screwdriver actuator to control the amount of hydraulic pressure acting on the clutch which is said by Scania to allow faster, smoother and more controlled gear changes.
After just a short test drive of the new two pedal transmission, the effect of the changes are very clear to the driver. The reaction by the transmission to the inputs by the driver on the accelerator is swift and precise. An aggressive right foot movement gives the driver quick acceleration with engine rpm levels allowed to rise relatively high before the upchange is made. More gentle movements on the accelerator achieve a smooth slow acceleration using less fuel.
This improved responsiveness to inputs from the right foot of the driver on the accelerator also comes into play when the truck is put into maneuvering mode. When this mode is activated the movement of the accelerator from the off position to full on represents about 60 to 70% of the rpm range in normal driving. This gives the driver the opportunity to feather the rpm levels, and through the software of the new Opticruise, feather the clutch, making for very precise slow maneuvering. This driver managed to lift the rear axle up onto a small piece of timber and park it precisely under the centre of the axle with relative ease, demonstrating a very forgiving system.
Scania has always been cautious and conservative when introducing change and there will still be a three pedal option on all of its trucks in the market next year. The decision has been made to retain the three pedal Opticruise when coupled with a V8 engine. The two pedal gearbox is standard with the new 13 litre engine so it can probably be assumed that the fully automated Opticruise will become available on the top power trucks as standard when new engine technology and control systems are introduced on the 15.7 litre V8 engines.
The results of the introduction of the new fuel injection technology on the 13 litre engine as well as its new computerised control systems combine with a new more responsive automation software and technology on the gearbox. These changes play to Scania’s strengths which have always been about integration of the entire system to increase smooth running and ease-of-use.
From the driver’s seat these new systems do make the job of getting a truck and its load from A to B just a little bit easier. The gear changing appears to be seamless and the updated software seems to be making gearchange decisions quicker and more accurately. The Opticruise is also a little better at anticipating what may be needed in the road ahead. The inclusion of an inclinometer in the gearbox system has given it better information and as a result it will try to set off downhill in a higher gear and take gear changes earlier to keep rpm high when climbing.
The testing available to Prime Mover in the limited environments of the test track at Anglesea was not sufficient for a driver to get a real handle on the improvements to the Scania systems. However, this preview does sharpen the appetite for more substantial test-driving and a real workout for the new technology.
