BMW confirms quad-turbo inline-6 diesel engine! - Team-BHP
BMW's amazing new 381 bhp 740 Nm 45 mpg triple turbo diesel (and four cars that will get it)
The new BMW M550d xDrive.
In for an engine rebuild: my BMW M550d Touring. Factory specs: tri-turbo diesel, 0-60 mph in 4.6 s. My engine's additional spec: leaking cylinder head. : r/Justrolledintotheshop
Four turbos are better than three: BMW debuts new quad-turbocharged diesel engine
BMW Tri-Turbo Diesel Engine Explained in Video | AutoGuide.com
Report: BMW's Next Diesel Engine Will Have FOUR TURBOS – News – Car and Driver