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AD&P; > March 2014 > FEATURE > Volvo's Drive-E: Environmentally Efcient—& Clever—Powertrains > Gary S. Vasilash > gsv@autofeldguide.com 24 AD&P; > March 2014 > FEATURE > Volvo's Drive-E: Environmentally Ecient—& Clever—Powertrains > Gary S. Vasilash > gsv@autofeldguide.com There is also a driver-selectable ECO+ button that, when engaged, not only performs stop-start when the vehicle is stopped, but also provides "ECO-coast," which disengages the engine brake when the driver lifts from the accelerator, thereby putting engine speed down to idle speed, but which also initiates "ECO-climate," which disconnects the air conditioning compressor (given the temperatures in Sweden, this is probably a reasonable thing; know that it can be overridden by pressing the AC button). Volvo has made a $300-million invest- ment in its plant in Sköve, Sweden, with fexible manufacturing equipment that permits the engine variations to be readily handled in production. The T5 engine produces 240 hp and 258 lb-ft of torque. The T6 engine produces 302 hp and 295 lb-ft of torque. The diference between the two? The T5 features an integrated sheet steel manifold turbocharger. The T6 not only has the turbocharger, but a supercharger, as well. Larsson explains that they opted to go with the turbocharger and the supercharger rather than twin turbochargers because with a four cylinder engine, that would mean that there would be two cylinders each for the turbos, which wouldn't provide high output especially at the low end. If there were serial turbochargers, then they could run to a problem with high backpressure, which would lead to performance problems. So for the T6, the clutchable roots- type supercharger is geared to provide low-end torque. Then, when sufcient speed is reached, the supercharger is disengaged and the turbocharger is deployed to improve performance. "The biggest struggle," Larsson admits, "was to make them work together with the control software." So what about the CO 2 ? The Drive-E powertrains are available in three Volvo vehicles in the U.S. at present: The S60 sedan, the V60 wagon (T5 only), and the XC60 crossover. According to certifcation under the New European Driving Cycle, the S60 with a T6 has CO 2 emissions of 149 g/km. With the 240-hp, T5 engine, it is rated at 137 g/km. (In case you are wondering about miles per gallon, the S60 T6 provides 24/35 mpg and the T5 25/37 mpg). In the development of these powertrains, Volvo engineers worked hard at providing all manner of improvements to achieve their goals. For example, the cast-in cast-iron cylinder liners are sprayed with eutectic aluminium to improve the bonding of the liners to the block. The pistons have reduced friction thanks to a PVD coating on the top ring and new honing specifcations. Piston pins are coated with diamond-like coating (DLC). An electric water pump is used in the gas engines to reduce friction losses and to facilitate fast engine warm-up. And on it goes. Larsson explains that when Ford purchased Volvo, powertrain engineering was something that became of reduced importance in Sweden, given that Ford was to become the predominant supplier of engines. But as the sale of Volvo to another company started to take shape, the powertrain engineering ranks were bolstered. And with the ownership by Geely, which is making an $11-billion investment in Volvo's technology, powertrain developments are back to the fore. And it is clear that Larsson and his colleagues are excited about what they've developed. p With a Drive-E T6, the Volvo S60 is rated at 24 mpg city, 35 mpg highway, 28 mpg combined. 0314ADP FEATURE Volvo.indd 24 2/18/2014 3:30:27 PM