Scania's latest models feature a wide range of Euro-3 engines boasting improved driveability and Opticruise automated transmission.
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Scania reveals spring models
• by Toby Clark
Scania is eager to show that it is—and will remain—a viable independent brand. The impending takeover by Volvo is likely to lead to a change in marketing emphasis, and the deal is still subject to EU approval (due in March), but Scania's 4Series range still has a lot of life in it.
The latest revisions are intended to reinforce Scania's image as a "green" brand, with environmentally friendly solutions to a number of haulage tasks. These include a wider range of Euro-3 diesels, a factory-fitted CRT particulate trap for nine-litre models and a new 11litre natural gas engine (see panel).
Next spring the range will be completed with Euro-3 versions of Scania's 14-litre V8.
One of the biggest changes for many operators will be the introduction of Opticruise throughout the range from 230hp upwards, and on all Euro-3 chassis including the construction variants. This automated transmission system is based on Scania's eight and 12speed synchromesh gearboxes; it incorporates cruise control and, if Scania's hydraulic retarder is fitted, a speed-hold control for hill descents.
However, unlike competing systems from ZF and Eaton. Opticruise remains a three-pedal system, using the clutch for shunting and coming to a standstill.
Braking has been upgraded with a "second-generation" EBS (electronic braking system) incorporating a trailer control module to improve brake compatibility between tractor and trailer. The new system "learns" the weight of the trailer, gaining a rough estimate of the weight from the first two or three brake applications and refinng it over the next 10 applications. The result should be more evenly-matched braking on all axles, and more even brake wear. This system can be retrofitted to existing EBS-equipped Scanias.
Scania has also increased the oilchange intervals for some of its Euro-2 engines—available until the Euro-3 deadline in October 2000. The 11,12 and 14-litre engines will now have maximum oil change intervals of 120,000km using Scania's own (non-synthetic) long-drain oil.
The chassis hasn't been neglected: some cab panels are now made from thinner, high-tensile steel, reducing weight by up to 60kg. Scania has introduced what it calls an "interacting subframe"—the bodywork subframe is riv eted and welded to the chassis rather than being bolted; this improves the unit's strength so the chassis and subframe can be downrated to save at least another 200kg.
Bodybuilders will welcome the introd ucton of precise chassis drawings, available for each vehicle on paper or over the Internet.
Scania's lighter tandem bogie (rated at 19 or 21 tonnes) is now available with disc brakes, and component changes have reduced its weight by 30kg. Finally, the 4-Series' low-height chassis is now even lower at 80mm below the standard chassis.
Mindful of the introduction of fleet management and on-board monitoring systems (described by Scania as Intelligent Transport Systems) the firm has introduced a one-way interface box to make data from the CAN bus available to external equipment. This will allow remote monitoring of engine, transmis
sion and electrical systems and it incorporates a "firewall" to prevent interference with these on-board systems.
Scania's Euro-3 diesels all use electronic injection control (EDC) or electronic unit injectors (EUI) but some of the Euro-2 models are still equipped with mechanical injection. Electronic injection results in more torque at lower revs and over a wider range. What it does not do is improve the peak efficiency of the engines: minimum specific fuel consumption has actually been hit by the Euro-3 requirements, although the more flexible torque characteristics will mean fewer gear changes and (potentially) better real-world fuel economy.
Euro-3 regulations
• The Euro-3 emissions regulations for new diesel vehicles will come into force on 1 October 2000.
The regulations cover two different test cycles: a steady-state cycle, applied to conventional diesel engines, and a transient test cycle which will be applied to vehicles fitted with exhaust after-treatment such as particulate traps.
They will make it harder than ever to deliver good fuel consumption because they constrain the conditions under which combustion can take place. But manufacturers have used electronically controlled fuel injection systems to good effect, and the practical effects on fuel consumption may be minimal.
When the next round of regulations come in (Euro-4, due in 2005) the steady-state and transient tests will both be applied, and the limits will be much tougher.
The emission limits for carbon monoxide (CO), unburnt hydrocarbons (HC) and oxides of nitrogen (N0x) will all be cut by around a third, while particulate emissions (PM) will have to be reduced by 80%. Despite the best efforts of the manufacturers, improved injection technology alone is unlikely to be enough to meet Euro-3; some form of after-treatment will probably be needed. This will almost certainly lead to a significant drop in fuel efficiency
Driving impressions
• Scania's latest engines seem to make the most of electronic diesel control, delivering smooth power from 1,000rpm or less. The 11-litre engine, with its lower reciprocating mass, is slightly smoother than the 12-litre unit.
The driveline becomes much more interesting with the addition of Scania's retarder: this works powerfully throughout the rev range and incorporates a useful speed-hold facillty.
The Euro-3 R114 380 coped well both up and down the hills of the Belgian Ardennes loaded to a full 40 tonnes; with Scania's 12-speed manual box it was easy to keep it in the heart of the green band.
The 12-litre, 420hp engine was shown to advantage in a 40-tonne drawbar outfit. With full air suspension and disc brakes all round the ride was impressive and it was an easy drive. The same driveline powered a tractive unit equipped with Opticruise: this system proved easy to learn and generally effective, though a skilled driver could doubtless ''out-think" it. Opticruise proved surprisingly effective in a 4x2 18-tonner, the P94 230. Controlling an eight-speed box, it made a smooth job of negotiating A-roads, hills and roundabouts, though the need to dip the clutch when coming to a halt would limit its usefulness in town. Scania also demonstrated its modular philosophy by showing an R94. This large-cab tractor had a nine-litre engine rated at 300hp and proved particularly flexible at 32 tonnes gross. From February operators will be able to specify a Pcab tractor with a 12-litre, 420hp engine.
Environmentally optimised trucks
• Scania has introduced a range of "environmentally optimised" trucks, making it easier for operators to present customers with a green fleet.
Recommended features include Euro-3 engines, air management kits, low-rolling-resistance tyros and smaller cabs to save weight. Scania even suggests operators look at their consumption of chassis lubricating grease—it reckons a heavy truck drops around 5kg of grease on the road in a year—and advises that chassis are greased manually, Another recommendation is a PTFE or solid lubricant-coated fifth wheel rather than a conventional unit.
Scania has also developed a continuously regenerating particulate trap (CRT) for its nine-litre engines, with a catalytic effect said to reduce HC, CO and PM emissions by 90%.
An 11-litre, 260hp spark-ignition engine has joined the range; it runs on compressed natural gas (CNC) or blogas—methane generated from organic waste matter