When the second generation Stralis Hi-Way’ smart fuel saving was unveiled to the press (it went on to win the International Truck of the Year award for 2013) the Italians made great play of the fact that the driving force behind their new long-haul heavy was a major reduction in its Total Cost of Ownership (TCO). Here is a brief run down on the latest Stralis range from Diesel News’ European Correspondent, Brian Weatherley.
Thanks to major savings in fuel the latest range-topping Stralis ‘XP’ (it stands for Extra Performance) offers long-haul operators significant reductions in CO₂ emissions too. So much so the clever marketing folk in Turin are calling their Stralis XP flagship a ‘TCO₂ Champion’…(TCO/TCO₂ geddit?)
Underneath the cab is where the major fuel-saving changes can be found, in particular the latest Euro 6 ‘C’ Hi-SCR Cursor 9, 11 and 13 in-line six diesels, which boast lower internal friction, thanks to re-profiled pistons and a revised ring pack, better thermal management, a new anti-idling function and, on selected long-haul Stralis XP variants, so-called ‘Smart’ engine auxiliaries to prevent parasitic losses when they’re not needed.
These include the clutch compressor and air-processing unit, an energy-recovery alternator with intelligent battery monitoring and a variable-flow steering pump. Smart ancillaries are definitely the in-thing for all the engine-makers right now, or at least until the next major step-change improvement in engine brake thermal efficiency comes along in the shape of waste-heat recovery, something Iveco is also working on.
The Euro 6 Cursor engine line-up remains virtually unchanged in terms of power and torque outputs. New arrivals are the 480hp top-rating on the Cursor 11 and the slightly-more powerful (by 10hp) range-topping 570 hp Cursor 13 (for Europe). Both feature what Iveco calls ‘Smart EGR’.
What the Italians have done on both these engines is to advance their injection timing to get better combustion and improved fuel economy. Naturally, the downside of advancing the timing is you create greater heat inside the combustion chamber, which produces more NOx. Not what you want.
However, by adding a small amount (only eight per cent) of exhaust gas recirculation back into the combustion chamber the engine-out NOx levels on the 480 and 570 Cursor remain the same as before, with the exhaust gases treated in the normal way by the Italian ’s Hi-SCR (selective catalytic reduction) system, without any change in AdBlue dosing levels.
The fuel savings of Smart EGR alone are roughly between 1 and 1.5 per cent. Other energy-saving engine enhancements include, the new reduced friction 2.47:1 Meritor back-axle (it’s the longest ratio in its class and lowers engine revs by seven per cent), the latest low-rolling resistance triple ‘A’ X-Line Energy Michelin eco tyres, plus the all-new Hi-Tronix 12-speed gearbox and the GPS-based Hi-Cruise predictive cruise control with eco-roll, and together they all add-up to 11 per cent fuel gain. Overall the new driveline changes represent a double-digit improvement over the previous Stralis.
Talking of the Stralis ’s latest Hi-Tronix two-pedal auto, it represents the very first installation of the all-new ‘TraXon’ automated transmission from ZF in a European heavy truck chassis. Hi-Tronix takes over the cog-swapping duties on the Stralis from the previous AS-Tronic auto, again supplied by ZF but called EuroTronic by Iveco.
Meanwhile, Iveco ’s chassis engineers have also got in on the act by completely redesigning the Stralis’s rear suspension which, while more durable is actually lighter to the tune of 45 kg. Higher resistance to corrosion, achieved with surface treatment of all key metallic components, means lower maintenance costs too. Last but not least, New Stralis has a completely new electrics and pneumatics layout which has helped bring repair and maintenance costs down by between five and eight per cent compared with the previous models, further underpinning Iveco’s commitment to reduce its overall TCO.