According to a Twitter update from the folks at Automobile, BMW will be ditching the naturally aspirated 3.0-liter inline-six in the base Z4 roadster in favor of a turbocharged four-cylinder powerplant. Big news, yes, but it doesn't come as much of a surprise since BMW has long flirted with the idea of using turbocharged four-pot mills in its base models like the Z4 sDrive30i and even the 328i.
Details are slim (curse you, 140-character limit), but Automobile states that because this new turbo four would replace the naturally aspirated six, at least 200 horsepower should be on tap. We'd expect a slightly higher output, since the current engine cranks out 255 horsepower and 220 pound-feet of torque. We certainly won't mind a turbocharged four-banger with gobs of low-end power under the hood of the Z4, and we'd expect to see this new mill show up within the next year.