Volvo’s rejuvenation started with the gorgeous Concept Coupe making its début at the 2013 Frankfurt Motor Show. Followed in short order by the Concept XC Coupe and the Concept Estate, they all hint at the future design language of medium-to-large Volvo road cars. Then came the revelation that all their future large cars will be built using their new Scalable Platform Architecture (SPA), followed by the unveiling of a key component of this new architecture: the all-new Drive-E powerplants.
To make sense of all this, let’s first examine the significance of SPA, and its implications for future Volvos. SPA will enable Volvo to cost-effectively engineer a wide range of vehicles by stretching a single basic floorpan in various directions. To accomplish this, they will use a standardised set of components, designed to fit across the range. Obviously, this platform need to work with different drivetrain layouts (FWD or AWD) and hybrid systems.
Component sharing within SPA is one of the motivations for the new Drive-E powertrains, simplification is another. Volvo’s current engine range comprises a vast spectrum of four-, five- and six cylinder units, often from different engine families, and mostly antiquated by now – the fives and sixes are relics from the 1990’s. Adding some gratuitous confusion, they also use two different four-cylinder units: a Peugeot 1.6T, and a Ford EcoBoost-derived 2.0T. This bewildering array of disparate and unrelated engines have made the under-bonnet engineering of the S/V60 a real challenge.
Characterful and powerful though the warbling old five- and six-potters were, they now lag behind the exhaust emissions of their ultra-efficient German counterparts. As an example, the old S60 T6 produced 225 kW and 400 Nm, yet belched out 237 g of CO2 every kilometer. The similarly powerful BMW 335i emits only 169 g of CO2 per kilometer, and as any new-car buyer knows, that makes a huge difference on the CO2 emissions tax.
Volvo’s solution to these contradictory problems (lower consumption and cleaner exhaust gasses while maintaining competitive power) is two-pronged. The first solution comes in the form of downsizing. While the Peugeot-sourced 1.6T engine will remain in the short term (after which it will be replaced by a three-cylinder version of the Drive-E engine), all the bigger engines will be replaced by some version of a brand-new 2.0-litre four-pot, in both petrol and diesel derivatives.
This is where it gets complicated, though. All versions of the new engine boast some form of forced induction, only varying boost pressure and turbo setup to achieve the desired power outputs. The T6 gets a twin-charger setup, which uses a supercharger to boost bottom-end torque and a bigger turbo to sustain top-end power, while the D6 has a twin-turbo unit. All other versions use a single turbo. The T6, incidentally, still produces 225 kW and 400 Nm, but the CO2 emission drops to a class leading 149 g/km – identical to the far less powerful BMW 328i.
The new engine is rather clever, as a modern, clean-slate design should be. Petrol- and diesel engines share the same block and crankshaft, with only the fuel injectors, cylinder heads, connecting rods and piston design being different. This favours standardised engine mountings and allows model variants to offer different powertrain options without increasing complexity.
The diesel versions of the Drive-E engines also pioneer a brand-new Denso fuel injection system, which uses intelligent fuel injectors which measure the actual fuel pressure. This enables the injectors to autonomously adjust the fuel delivery to ensure a more efficient combustion process, lower emissions, more power, and a smoother power delivery.
Drive-E also emphasises a reduction of internal friction, including a redesigned and very rigid crankcase frame, and roller bearings for the twin overhead camshafts. Engine temperature is electronically controlled to ensure a quicker warm-up, and continuously variable camshaft timing optimises the engine’s breathing for efficiency without compromising power.
Volvo didn’t stop at the new engines either, for the Drive-E engines will be mated to either the current 6-speed manual transmission, or a new 8-speed torque converter autobox. This new gearbox weighs 7.5 kg less than the previous 6-speeder, and contributes to a total weight saving of up to 35 kg. As an added advantage, the Drive-E engines are already compatible with electrification, meaning that hybrid technology will be added at a later stage.
We sampled the new Drive-E systems on launch recently, see what we thought HERE.
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Written by: Martin Pretorius
