THE SING CONCE Scania has revised the 4-Series with new
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engines and cab layouts. First seen at the Amsterdam Show in February, the changes enter production this month: new 11 and 12-litre units (rated at 340, 380 and 420hp) feature electronic unit injectors, and can be matched to Scania's Opticruise automatic gearbox system. The existing 12-litre units—the mechanically injected 360 and the EDC-equipped 400hp version—remain in production.
The cab changes reflect the western European move towards long-haul, single-driver operation: the latest P-cab, the larger R-cab and the highroof, high-spec R Topline cab can now be optimised for one person, with more accessible storage space and an improved rest area. CM has been to Germany to drive the new trucks and find out more.
by Toby Clark • Most long-haul tractor customers want a two-bunk set-up, but Scania believes that the trend is towards one-person operation. Thomas Bertilsson, Scania's sales director for central Europe, says: "In eastern Europe they can still afford to have two drivers. Even in the West, customers like two beds—but perhaps not in five years' time."
Scania's revised cabs, available alongside the existing ones, offer more comprehensive storage, rear-set passenger seats for a resting driver and improved bunk access. A driver's-side airbag and seatbelt pre-tensioners are also available in the Pcab as well as the R-cab.
The latest R-type sleeper has some superb refinements: a pull-out document drawer in the dash; an excellent, simple cupand bottle-holder; and an optional flip-up table, mounted on a large slide-out locker with a washable interior.
The passenger seat is positioned against the rear wall to give excellent leg room and more changing space on the floor.
Cross-cab access is helped by a lower, flatter engine hump, while the steering wheel and gear lever can fold out of the way. The back of the passenger seat can be flipped down onehanded to let the bunk down.
The Topline cab is still cavernous and, to the surprise of some sceptical operators, it retains its controversial frontmounted main bunk above the windscreen—there is a smaller, rear-mounted lower bunk for occasional two-person use. Access to the upper bunk is improved: the driver's seat can slide back to the rear wall, and the flip-down access ladder is now wider. DIIVING IMPRESSIONS CM h engine, r.
The 3: peak tor stroke m smoothl The lo smoothe though t retarder day with The presiden tic UK 01 ous choli tackling in its eig We alnow ava 530hp an d the chance to drive the old EDC-equipped 12-litre ted at 400hp, back-to-back with the newer engines.
hp 11-litre unit compares well, having a slightly lower ue rating but a broader spread of power. The shorter ns that it revs much more willingly, and it runs more in its green band.
ger-stroke 420hp unit is a little less eager, but is still than the 400—it is even tolerant of three-figure revs, ese are hardly efficient. Mated to Scania's cruise control, nd speed-hold facility, it could keep a constant speed all little effort.
hp engine could be popular: Lars Orehall, Scania's vicein charge of powertrain development, says: "For domesration I'd be disappointed if the 340 were not the obvie." Even at 40 tonnes all-up, it accelerated vigorously, gruelling 4% grade without dropping below sixth gear t-speed box.
o had the chance to drive Scania's Opticruise gearshift, lable on unit injector and EDC engines from 400 to on 11-litre models from September.
The system retains Scania's 12+2 synchromesh gearbox, but adds electronic synchronisation and electro-pneumatic shifting for fully automatic operation—the clutch pedal is used only when starting and stopping and for lowspeed manoeuvres. The system is easy to use and works reliably but, like all auto systems, it cannot read the road ahead; a canny driver can achieve better performance and fuel consumption. Still, it can promise consistent results from a fleet of variable drivers. FUTURE SCANIA ENGINES1 • Lars Orehall, Scania's vice-president in charge of powertrain development, says: "We believe strongly in driveability. It should not be difficult to drive a modern truck." So the new engines have a broader spread of peak torque, and can be combined with Opticruise.
Orehall adds: "Unit injection is better matched per cylinder— it's an even engine." And a successful combustion chamber and injector can easily be duplicated in another engine.
Scania still believes in modular design; this suggests that Scania's 9-litre engine could be replaced by a five-cylinder version of the 11/12-litre unit.
But Orehall does not discount the possibility of Scania buying in engines. "Outsourcing components could be worthwhile," he says. "If someone can deliver engines to a lower cost we should look into it. But if we can keep engines in our own hands it has a terrific upside."
With increasing power outputs from the straight six, what about the 14-litre V8? Orehall confirms that a unit-injected version will be available for Euro-3, suggesting the possibility of higher outputs than the current 460 and 530hp.
Beyond Euro-3, Scania is still looking at turbo-compound engines to eke out the final ounce of efficiency from diesel power, and at conventional diesels with some refinements.
"The main dilemma with Euro-4 is nitrogen oxide levels," says Orehall. If legislated levels are too low "other techniques should be used". These could include a urea catalyst, in which an ammonia-based liquid is injected into the exhaust flow to reduce nitrogen oxides to nitrogen. The technique is well known, but it has practical problems—a truck might need a 50-70 litre tank of urea on board. Higher injection pressures and cooled EGR (exhaust gas recirculation—see CM 4-10December 1997) are other options.
Scania has built diesel-electric hybrid, gas-powered and ethanol-fuelled buses for urban applications. Stockholm is taking delivery of 35 ethanol-powered articulated buses which will be used on routes formerly plied by trams. But Orehall believes that alternative fuels will remain viable only for specialist applicafions: "I am 100% sure that in 10 years diesel will still be the main fuel for heavy road transport."
• The new engines are developments from the previous 12-litre unit with the addition of unit injectors, each incorporating a camshaft-operated high-pressure pump, electronically controlled by a computer mounted on the cooler left-hand side of the engine block. The 420hp unit retains the same dimensions, while the 340hp and 380hp versions have a shorter stroke for a capacity of 10.6 litres.
Like Dal's recent CF unit, the engines are designed to have a large "sweet spot"—according to Scania, most trucks spend 85% of running time at less than 80% of maximum torque. So the engines are most efficient in the middle of the green area on the rev-counter and at just below peak torque—and should be tolerant of less-thanperfect drivers.