Diesel Lives!

Scania’s all-new 13-litre diesel engine is an important step in the decarbonisation of road transport.
Scania SUPER 13-litre B-double.

As most truck and engine manufacturers, Scania included, are charging towards the net-zero solutions of electrification and/or hydrogen power, Scania has developed what is very likely to be the last internal combustion engine (ICE) to be developed by the Swedish member of the Traton organisation.

Five years and two billion Euros have gone into developing the Scania SUPER range that goes beyond its Euro VI engine platform by incorporating new transmissions, new rear axles and even new chassis rails to produce a homogenous combination which delivers a very impressive improvement in fuel efficiency and reduced CO² emissions.

The SUPER range also represents the most comprehensive update of the Scania trucks since the introduction of the New Truck Generation into Australia in 2018.

The 13-litre SUPER engine is available in 420-, 460-, 500- and 560 horsepower ratings and is capable of delivering significant fuel savings, especially for long haul applications. Adding to the environmental credentials, the 460- and 500 hp versions can be run on up to B100 biodiesel.

All of the new SUPER engines can also run on hydrogenated vegetable oils (HVO). This new low-rev engine family is available with Scania P-series, G-series and R-series cabs and will be shared across other Traton brands including MAN.

Scania 13 litre engine.
Scania 13 litre engine.

In the engine’s development, a broad approach has been taken with fundamental changes such as dual overhead camshafts (DOHC) operating four valves per cylinder and a single piece cylinder head, to detailed reassessments of every other engine component.

The engines use ultra-thin long-life oils and auxiliary systems such as alternators and compressors which can be disengaged in order to reduce parasitic power losses.

There has been no carry-over from the earlier six-cylinder engine range to the new one, with essentially every component being critically examined and revised, from the injectors to the fuel pump.

Tweaks to such fundamental components as the crankshaft have contributed to an increase in the engines’ technical life of up to 30 per cent compared to the previous generation, despite extended maintenance intervals.

Scania’s Twin-SCR system, which was first introduced to Australia on the new 770 V8 in 2021, injects an initial dose of AdBlue close to the turbo immediately after the exhaust brake butterfly valve, where the exhaust gases are still very hot. The effect is to dramatically increase the total efficiency of the after-treatment system.

The second dose of AdBlue is then injected in the usual location inside the after-treatment system.

A particulate filter is positioned between the two SCR catalysts and is regenerated without post-injecting extra fuel to the exhaust system. The new after treatment system is a very compact one-unit solution and offers increased flexibility regarding its position and outlet directions which will be particularly appreciated by bodybuilders looking for space on the chassis.

An advantage of the DOHC configuration has been the development of the optional Compression Release Brake (CRB) system.

Scania SUPER 13-litre B-double test drive.
Scania SUPER 13-litre B-double test drive.

The new engine-integrated brake weighs only seven kilograms and provides a retardation effect up to 350 kW. The CRB components are all fitted within the cylinder head and involve a separate rocker arm which opens the exhaust valve during the compression stroke and releases the compression just before the piston reaches top dead centre.

Hot, compressed air is allowed to escape from the cylinder into the exhaust manifold, building up pressure which spools up the turbo and then exits via the exhaust system.

The CRB is activated either via the brake pedal or using the Retarder wand/gear selector or via steering wheel buttons. The design means the conventional exhaust brake and CRB cannot both be used simultaneously.

The CRB technology means that many combinations operating in certain locations will not need a gearbox-mounted Retarder, although for high gross weight applications such as interstate B-doubles it is likely many Scania customers will continue to specify the Retarder because of the added safety and reduced maintenance which accompany its maximum brake torque of 4700 Nm. The SUPER range also comes with a new range of diesel fuel tanks.

These have a D-shaped design which improves their robustness. The new Fuel Optimisation Unit is attached to the primary tank and works as a catch tank with electric pumps and ultrasound pressure sensors, enabling the truck to have ‘fuel on demand’ with exactly the amount of fuel the engine needs.

Our introduction to the Scania Super series is by way of a back-to-back drive of a 560R B-double grossing 60 tonnes, followed by a 460P single trailer combination grossing around 40 tonnes.

The route for each covers a 220-kilometre loop along the Calder Highway north of Melbourne. It includes hill climbing and descending, as well as traffic and road works typical of an Australian inter-city or interstate linehaul operation.

The Scania cabs retain their familiar well-thought-out interiors which focus on driver comfort and extensive support systems.

As a major component of the strategy to maximise fuel efficiency, the Opticruise transmissions in both trucks tend to only engage Overdrive when conditions suit.

We are told the new transmissions will do more shifting than we might expect, but the new boxes are so smooth and the cab interior so quiet, unless we are watching the indicator readout on the dash, we barely notice many of the shifts at all, particularly while maintaining highway speeds.

Scania introduced the first of its new range of automated transmissions back in 2021 with the overdrive top gear and “tall” diff ratios calculated to keep the engine operating at around the 1,200rpm mark when cruising at 100 km/hr.

The utilisation of faster rear axle gearing encourages running in 12th (direct) gear which provides the lowest transmission losses.

Scania 500 S 4x2 Highline fuel optimisation unit.
Scania 500 S 4×2 Highline fuel optimisation unit.

The rear axles also feature low friction bearings, lower hypoid offset and improved oil flow with reduced splash losses, all of which contribute to the fuel efficiency, while improved lubrication in combination with more precise machining of the internal components result in extended service intervals.

The G33CM Opticruise transmissions fitted to both prime movers are some 75 kg lighter than before due to all-aluminium housings and smaller overall dimensions. There are 14 forward gears, including a super crawler and the overdrive gear, and up to eight reverse ratios.

A pumped oil spray lubrication system contributes to markedly less internal friction and consequential component wear. Internal drag losses are reduced by 50 per cent, while the overall design has lowered the sound levels of the transmission by 3.5 decibels.

The powertrain in the SUPER models is an integrated unit where the engine, the after-treatment system, the gearbox and the driven axles all operate in harmony via sophisticated electronic management systems.

The combination of the new powertrain has enabled Scania to confidently claim an eight per cent fuel saving and early local trails running predominantly on regular diesel fuel have shown a percentile fuel efficiency improvement well into double digits, even when compared to the efficient engines they are replacing.

Scientifically, the thermal efficiency is around 50 per cent for the new engines. Not long ago this would have been unthinkable for internal combustion engines and is close to the efficiencies sought by Formula 1 teams.

It’s not all just about the driveline, and introduced in the SUPER range, Scania’s new Modular Architecture Chassis (MACH) provides a new structure for frame hole patterns, with dedicated holes for mounting components both inside and outside the frame.

The result is a more modular chassis, which increases the theoretical number of chassis layouts exponentially and increases opportunities for body builders to tailor trucks to best suit operator’s specific applications.

The ever-rising cost of diesel fuel and the need to control carbon emissions are two of the main drivers behind the development of the Scania SUPER range.

Significant improvements in fuel efficiency can be realistically achieved in many applications with these trucks, which will address those goals with current proven technology.

As development progresses on renewable fuels and zero emission vehicles and the infrastructure they require, it’s reassuring that an essentially conventional, albeit very sophisticated, diesel engine is available.

Send this to a friend