Say what you want about the way BMW's 6-series looks - please, we invite you, so long as you say that it's an ugly design, a set of oddball styling cues laid over otherwise fantastic proportions - but we've never been able to complain about the way Munich's biggest coupe drives. Now, in a distinct departure from form, BMW has decided to offer a diesel engine in its foremost grand tourer. And the fact that it won't come stateside won't keep us from singing its praises.
Like the similarly named 335d and 335i before it, the 635d is powered by a twin-turbocharged inline six displacing three - not, as the badge would indicate, three and a half - liters. The diesel three-liter boasts an aluminum crankcase, two-stage turbocharging (one small turbo, one large turbo; the small one works alone at low speeds, the small and the large one work together at high speeds), and common-rail fuel injection. Output is a claimed 286 hp and a truly ridiculous 427 lb-ft of torque. That ridiculous amount of thrust occurs at an earth-shakingly low 1750 rpm (maximum engine power comes at 4,400 rpm), and helps shove the big, heavy 635d coupe to 60 mph in 6.3 seconds. (The 635d convertible, being even heavier, takes an additional 0.4 seconds to reach the same speed.) Top speed is an electronically limited 155 mph, and BMW claims fuel economy hovers around forty miles to the gallon. 40 mpg! Cruising range, a modern diesel strong-suit, is just over 600 miles per one tank of fuel.
Oh, diesel: We love you so. Oh, how we'd love a big diesel grand-touring machine. Oh, how we aren't going to get one. Oh, how the world is filled with injustice...