The entry-level 2012 BMW 5 Series will switch to a 2.0-liter turbocharged and direct-injected four-cylinder that produces 240 horsepower and 260 pound-feet of torque. That's the same horsepower as the current car's 3.0-liter naturally aspirated inline-6, but 30 additional lb-ft of torque.
Power is certainly impressive, but this is clearly a move made for the sake of fuel economy. Turbocharging, direct injection, less weight, brake energy regeneration, an ECO mode, the eight-speed automatic and auto stop/start technology will result in a 15-percent improvement in fuel economy over the current 528i's already pretty impressive 22 mpg city/32 mpg highway and 25 mpg combined.
As BMW has completely thrown its naming convention out the window, the new entry-level 5er will not be the 520i, but instead remain the 528i. Wouldn't want your car to sound less fancy than your neighbors. Nor would you want to know your $50,000 luxury sedan has a ... gulp ... four banger. I say who cares, good power is good power, and the current 528i is not a slow car. The new engine should make it better regardless of how many cylinders it has. More info on the engine after the jump.
The new 2.0-liter four-cylinder will utilize much of the same technologies as the 3.0-liter turbocharged six-cylinder found in BMW's 35i cars. There is a single, twin-scroll turbocharger. Engineering editor Jay Kavanagh is out getting a coffee, so let's just go to the press release, "The exhaust streams leaving the two pairs of cylinders are kept completely separate as they flow through the exhaust manifold and the turbocharger, taking a spiral path to the turbine wheel. This configuration results in very low exhaust back pressure at low engine rpm, and allows the energy of the exhaust gas pulses to be optimally managed and translated into powerful rotation of the turbine blades, without a delay in throttle response."
Got that? Good, there will be a quiz later. All that torque developed will be available at just 1,250 rpm, which should make it feel pretty damn ballsy off the line. Should you want to quash some of that ballsiness with extra weight, or live in the snow belt (or are convinced by a dealer you need it for some creative reason in Southern California), BMW's xDrive all-wheel-drive system will be available as an option.
QUIZ: What type of path does the exhaust streams take while traveling to the turbine wheel?
