Why Scania's 11L donk is a game changer

With the phasing out of its long-serving nine litre engine, Scania has taken an innovative approach with its replacement; a new 11 litre engine with variable valve activation (VVA) to meet power, mass and emission requirements at the lighter end of its range.

The Swedish truck maker is claiming a seven per cent reduction in fuel consumption, compared to the engine it replaces. The 11 litre engine is said to include 85 per cent of the nine litre's architecture, while supplying higher torque at lower rpm levels.

It's also lighter than the lower powered engine it replaces. The 11 litre newcomer will be available at 350hp, 390hp, and 430hp.

So far, test drives of trucks fitted with the new engine have shown it to be both flexible and responsive, and well suited to the kind of tasks the lighter end of the Scania range will be expected to tackle.

The introduction of VVA has also transformed the engine braking capacity, with the Compression Release Brake combining and integrating with the VVA (controlled by the cam phasers) to achieve much improved retardation.

It's also a lighter system than the gearbox mounted hydraulic retarder used in previous models.

In a typically pragmatic way, Scania’s route to the new engine started with the engine development team using the existing 13 litre engine as a base. Removing one of the modular cylinders (from six to five cylinders) reduced power and weight.

An engine with an odd number of cylinders will often be found to have an inherent rod imbalance. The usual way to counteract this issue is by offsetting the crank pins plus twin counter rotating balance shafts lower down in the engine, with the aim of counteracting any problematic harmonics.

The other major change from the 13 litre engine is the introduction of variable cam timing. There are cam phases on the camshaft, which adjust valve duration and lift, and this changes as the engine moves across the rpm range.

This design is aimed at increasing low-end torque; in this case the engine reaches maximum torque at just 95 rpm, which isn't bad for a 10.6 litre engine! That level of torque is available all of the way to 1300rpm, giving the 11 litre a very flat torque curve.

The cam phase set up is not just for torque; it's also helping with fuel economy, under certain conditions, as it adjusts ignition timing and duration. The variable cam phases on the front of the camshaft are oil pressure driven, and work by actually moving the camshafts across and changing the running position.

With diesel engines in trucks, the camshaft is normally set up in one ideal position and that design ensures there's a sweet spot where power and torque are ideal. By going with a variable valve timing it's possible to move that sweet spot to suit different driving conditions.

Instead of developing a sweet spot at one specific rpm level, introducing VVA enables the designers to chase that sweet spot. The combination of valves opening and shutting, in conjunction with the firing order, will produce the best possible combustion for that rpm.

VVA also helps with emission control, enabling the designers to advance and retard ignition, as required.

The VVA results in a 400rpm range where all of the parameters for clean and efficient, power and torque production are maximised in the 11 litre engine.

The new engine ramps up to 950rpm and then maintains high-performance levels past 1300rpm. While performance does taper after that, it's no more than any other engine as it passes its sweet spot.

This 11 litre only uses SCR for emission control, which suits such a high compression engine. Manifold design, combustion chamber design, and exhaust manifold and turbocharger design are all working towards improved gas exchange at a high compression.

That level of compression will inevitably lead to higher ignition temperatures, and therefore higher NOx levels in the exhaust, but the SCR system has been designed to clean that up.

The SCR actually injects AdBlue directly into the turbocharger; another first for Scania. The new SCR is claimed to improve atomisation of the AdBlue, giving it a wider spread.

This new 11 litre is unusual in a number of ways.

For starters it's a five-cylinder, plus it's got variable cam timing, and an SCR system injecting Adblue directly into the turbo. These elements have allowed the designers to keep the rest of the engine design simple.

The 11 litre engine is also designed to fit in a relatively small envelope and in trucks which have traditionally used nine litre engines. However, it's only five kilograms heavier than the nine litre it replaces.

It has a compression ratio of 23:1, resulting in the block being made out of compacted graphite iron which can cope with higher pressure at the same weight.

Scania says the 11 litre powertrain is suitable for a range of applications including general cargo, tipper, flatbed/crane combos, hooklift, fuel delivery, car transportation, and waste collection.

With the new engine, the company is also looking to make some inroads into the concrete agitator market for the first time.

“We are confident drivers on distribution or vocational duties will notice the difference as quickly, as will the accountants reviewing operating costs," Scania Australia's Truck Sales Director, Benjamin Nye said.

"And with the success we have had with the Super 13 in Australia, there is no doubt that the benefits of the Super 11 family will go straight to the customers’ bottom lines."

Related: Scania Super 11 2026 Review