The 2015 Volvo S60 offers four different powertrains, two of them brand-new. And it's the new ones, both using the company's 2.0-liter Drive-E four-cylinder engine and an eight-speed automatic transmission, that produce the best fuel efficiency. The new models just keep Volvo competitive with BMW and Mercedes-Benz, which have already introduced similar turbocharged smaller fours, but they're a major advance over prior model years.
The new engines also come standard with start-stop, with we found to be very quick on the restart and easy to get accustomed to in traffic. And drivers can chose from three modes: Drive, Sport, and Eco+, which retune the power delivery and transmission shift points to provide quick response (Sport) or more fuel-efficient running (Eco+).
The drawback is that the new engines come only with front-wheel drive; if you want all-wheel drive, you're stuck with older, less efficient five- and six-cylinder engines. That won't change for a couple of years, until the S60 is redesigned to incorporate both the new engine/transmission combination and the company's Haldex all-wheel-drive system.
So, for front-wheel-drive S60 models, the T5 uses a 240-hp turbocharged Drive-E engine and the T6 boosts that to 302 hp by adding a supercharger as well as the turbo. The T5 is rated at 29 mpg combined (25 mpg city, 37 mpg highway) and the T6 at 28 mpg combined (24 mpg city, 35 mpg highway). Both vehicles benefit from very relaxed cruising at highway speeds due to the wide gear spread of the new eight-speed automatic.
But if you need all-wheel drive in your S60--as Volvo says 40 percent of buyers will--then the picture isn't as rosy. The five-cylinder T5 AWD model is rated at 23 mpg (20 mpg city, 29 mpg highway) and the more powerful six-cylinder T6 AWD S60 comes in at 22 mpg combined (19 mpg city, 28 mpg highway).
So give Volvo half-credit for improving part of the range--but if you want highly efficient all-wheel-drive S60 models, you'll have to wait a bit longer.