Scania has taken the unusual step of introducing second-generation Euro-6 engines nine months before Euro-6 emissions legislation is fully implemented at the end of this year.
When it unveiled its first Euro-6-compliant 12.7-litre engine two years ago, Scania said that testing showed fuel consumption was comparable with Euro-5’s. But now some competitors are claiming their new Euro-6 engines and trucks are more fuel-efficient than current models. And rivals such as Volvo, Mercedes-Benz and Daf are introducing new or face-lifted models that give operators something extra to soften the on-cost of Euro-6 trucks. This appears to have spurred Scania into raising its game: while unveiling the rest of its Euro-6 engines, it has revealed a range of fuel-saving additions that should mean its Euro-6 trucks are more frugal than its Euro-5s.
New engine ratings
Scania has upped the output of its two EGR+ SCR Euro-6 versions of the 12.7-litre DC13 engine, taking them from nominal ratings of 440hp and 480hp to 450hp and 490hp, with peak torque up by 50Nm to 2,350Nm and 2,550Nm respectively. There is also a new rating, 410hp, believed to be 3% more economical than the Euro-5 EGR 400hp engine. The 410hp engine uses just SCR rather than a combination of EGR+SCR to cut NOx, taking a leaf out of Iveco’s Euro-6 book. Whereas Scania’s EGR+ SCR Euro-6 engines use variable geometry turbocharging (VGT) to control manifold pressures to manage EGR, a simpler waste-gated turbo suffices for this SCR engine. The absence of EGR ducting and cooling is said to make this engine 40kg lighter than the 450hp rating. However, some of that saving may be lost by carrying more AdBlue: Scania said its consumption rate is about 6% of fuel consumption, roughly twice as high as the EGR+SCR engines.
Engine weight is becoming an increasingly salient issue for Euro-6 trucks burdened with extra exhaust after-treatment equipment. Scania’s decision to rationalise its Euro-6 engine range to three swept volumes – 9.3, 12.7 and 16.4 litres – comes at a time when other manufacturers are embracing down-sizing, anticipating a rosy future for 10.5- to 11-litre engines.
New Euro-6 engines from Daf (10.8 litres), Mercedes (10.7 litres) and Iveco (11.1 litres) will join engines from Volvo/Renault (10.8 litres) and MAN (10.5 litres). They promise lighter, more frugal engines in the 350hp to 430hp bracket, likely to appeal to operators of weight-critical multiwheelers and distribution tractors.
Scania will be tackling the lower end of this power band with a new 370hp rating of the 12.7-
litre. Going below that entails a step down to the five-cylinder, 9.3-litre DC09 engine. There are four Euro-6 ratings of this engine – two EGR+ SCR, two SCR only – covering the territory between 250hp and 360hp, supplemented by a pair of gas versions at 280hp and 340hp.
The 15.6-litre V8 engine doesn’t make the transition to Euro-6. Instead, all three ratings of the Euro-6 V8 are based on the 16.4-litre engine used only at 730hp. Scania is starting with just two, 520hp and 580hp, with 730hp due by year end. With nothing in the 600hp to 700hp range, this leaves a 150hp gap in ratings. However, Scania said the new 580hp has a ‘fatter’ power curve and almost as much torque as a Euro-5 620. All three use EGR+SCR and variable geometry turbocharging.
Scania advises operators to steer clear of high-power ratings at Euro-6 if their engines seldom run at full load. They risk running too cool to allow the exhaust after-treatment catalysts to work effectively, which will trigger the engine to burn more fuel simply to raise the exhaust temperature. It would be better, says Scania, to choose a less powerful engine and work it harder to keep the exhaust hotter.
Economy improvements
Scania said all its second-generation Euro-6 engines are 2% to 3% more fuel efficient than the first ones. The savings emanate from reshaping the piston bowl, low-friction coating on the cylinder liners and a pneumatically controlled clutched coupling that disengages the engine’s air-compressor when not needed.
More fuel-saving measures
These improvements, which apply to all Euro-6 engines, are packaged together with other fuel-saving measures on new Streamline versions of Scania’s G- and R-Series long-distance haulage models. Streamline units include Opticruise automated gearboxes and Scania Active Prediction terrain-sensitive cruise control as standard, each said to boost fuel economy by 2% to 3%. They also have the factory-fit full air-management kit, helped by the addition of lips on the cab corner-deflectors and a revised sun-visor, claimed to help smooth airflow on the leading edge of the roof.
A new economy mode – supplementing the existing standard, power and off-road modes – can be programmed into the Opticruise control system. This disables the gearbox’s kick-down function, applies a speed limiter setting of either 80km/h or 85km/h, ‘softens’ engine response and modifies the action of the cruise control to allow the truck to gain more speed beyond the set maximum on downhill gradients to conserve fuel when the road levels out.
Scania’s in-house Communicator telematics system, which holds the 3D mapping data
for the cruise control system, has a new remote diagnostics function, allowing the workshop
to download all the truck’s relevant data ahead of a planned service, increasing the chances of a first-time fix. Other changes include new headlamps (standard on all G- and R-Series sleeper cabs, optional on all others) and the option of LED rear-light clusters for all models. Quite apart from their durability benefits, Scania also identifies a tiny fuel saving (30 litres annually) derived from the use of the LED rear lamps.
To cope with the chassis-packaging issues associated with Euro-6, Scania has come up with some alternative new AdBlue tanks, which are shaped to sit out of sight on the inside of the chassis main rails. These are available with volumes of up to 100 litres, which is big enough to suit the higher AdBlue consumption rates of SCR-only engines. Finally, there is the option of a new battery system, using two pairs of small 12V batteries, each pair specified for either high power (for vehicle starting) or deep discharge (for running ancillary electrics).
Separating the two functions and tailoring the batteries to suit should be attractive for any LGV with high-electrical demands.
N.B: The article appears in Commercial Motor magazine, on sale tomorrow (4 April 2013)
