The Smaller, the Better
by: Bernard Hellberg Sr
If renowned Swedish carmaker Volvo has its way, the complex and costly tradition of manufacturers developing ever increasing permutations of engines to match ever expanding product line-ups will take a dramatic turn for the uncomplicated.
The company’s new Drive-E range of powertrains takes driving pleasure to a new dimension in which output and efficiency – rather than the number of cylinders – determine the quality of performance. Smooth, balanced and ultra-efficient, these new two-litre, four-cylinder Drive-E powertrains offer a world-class blend of drivability and low CO2 emissions.
For Volvo Cars this is the perfect powertrain solution for customers, especially for those countries where flexifuels, as well as electric and hybrid technologies are not yet feasible. The Drive-E engine range is a major achievement for Volvo Cars, and shows the company’s dedication to improving fuel consumption and C02 figures without sacrificing performance.
Volvo’s eight engine derivatives that currently power the Volvo line-up will gradually be replaced by only two: a four-cylinder Drive-E petrol engine, and a four-cylinder Drive-E diesel. These two engines can be configured to meet the power and output needs of the entire Volvo range, from the Volvo V40 hatchback to the future Volvo XC90 SUV.
Imagine, for example, a 2-litre petrol engine that can be shaped to offer anything from 133 kW to 225 kW, while delivering fuel economy ranging from 4.1 litres/100 km to 6.4 litres/100 km for the higher-spec version.In the words of Derek Crabb, Vice President of Powertrain Engineering at Volvo: “These technologies give the customer high performance, improved fuel economy, considerably lower emissions, and even the bonus of powerful sound. These four-cylinder engines offer higher performance than today’s six-cylinder units and lower fuel consumption than the current four-cylinder generation. An added bonus is that we now outperform competitors when it comes to power versus CO2 emissions.”
Significantly, eight power derivatives will be on offer and the fuel economy will improve by between 15 % and 35 % across the board – with a weight saving of 30 kg to 50 kg per engine.
The first of these new Drive-E engines – the new Drive-E T5 petrol and the new Drive-E D4 diesel – are now available across the Volvo 60s range. This means that the Volvo S60 sedan, Volvo V60 sportswagon and the Volvo XC60 SUV now have new engines specifically set up for each application. Volvo’s top-of-the-range T6 Drive-E petrol engine will follow at a later stage, but with 225 kW and CO2 emissions at 149 g/km, the Volvo S60 T6 is set to be the first car in its segment that offers over 100 kW/litre, while being capable of accelerating from 0-100 km/h in just 5.9 seconds.This new 2-litre, four-cylinder T6 engine features both a supercharger and a turbo charger. Using the supercharger to fill in the bottom end torque gives the petrol engine a big, naturally aspirated feel. The mechanically linked compressor starts to function immediately at low revs, while the turbocharger kicks in when the airflow builds up.
To deliver the desired responsive, smooth, and fuel-efficient drivability, the engines are teamed either with a new eight-speed automatic gearbox, or an enhanced six-speed manual, tuned for improved fuel economy.
Volvo Cars’ powertrain experts have developed the engines in-house and production is at Volvo Car Group’s high-tech engine plant in Skövde, Sweden.
The diesels boast world-first i-Art technology. By featuring pressure feedback from each fuel injector instead of using a traditional single pressure sensor in the common rail, i-Art makes it possible to continuously monitor and adapt fuel injection per combustion in each of the four cylinders.
Other improvements to the Drive-E petrol engines include friction reduction measures such as ball bearings on the camshaft, high-speed continuous variable valve timing, and intelligent heat management with a fully variable electric water pump.
Prophetically, Crabb sees Volvo’s engine future in the following light: “The power you get from an engine has nothing to do with its size; it is about the amount of air that you can get to flow through it. You can also make an engine more efficient if you make it smaller. So, if you can get more air through a smaller engine, you can still get the same power, but at better efficiency.”
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