Just when we were beginning to lose faith in BMW, rumors begin to surface on a crazy new triple turbocharged diesel engine for an X5 Performance Diesel package. Intriguing would be an understatement.

According to unconfirmed reports, BMW has completed development on a tri-turbo version of the twin turbo diesel straight six already doing duty under the hood of the X5. The current 3.0-liter, twin-turbo I6 makes 265 HP but reportedly this upgrade would push output to a heady 354 HP with untold mountains of torque. It would be marketed under the Efficient dynamics banner and get a start-stop system and a regenerative braking system as well. We're most interested to learn how routing two cylinders of exhaust for each turbo will look, should this tasty rumor turn out to be true. [BMW Blog]

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