BMW 7 Series to get quad-turbo diesel?

Sometime in 2016 BMW will ask its customers, “Would you like more turbos with your turbos?” Reports are the Bavarian company is working on an inline six-cylinder quad-turbocharged 3.0-liter diesel engine to replace the tri-turbo 3.0-liter diesel currently used in performance products like the all-wheel-drive X5 M50d and X6 M50d sold in other markets.