Under the hood is BMW’s most powerful turbo-diesel engine, a 3.0-liter straight-six with no fewer than four turbos, 382 horsepower, and 568 lb-ft of torque from as little as 1750 rpm. It’s the formidable and forbidden engine that also appears in the Euro-spec M550d and 750d (and one-ups BMW’s tri-turbo diesel in the previous-gen M550d and current X5 and X6 M50d). Alpina promises a zero-to-62-mph time of 4.6 seconds and a 165-mph top speed, which is nearly in line with the 355-hp 2018 X3 M40i we tested.
Oddly, right-hand-drive models bound for the U.K. come with BMW’s twin-turbo diesel six, which cuts output to 329 horses and 516 lb-ft. That’s even less powerful than Alpina’s previous twin-turbo XD3. Sorry, blokes.
Outside the engine compartment, the XD3 receives the usual ultraclassy Alpina treatment, with a custom chin spoiler, Alpina brake calipers behind oh-so-gorgeous 20-spoke wheels with hidden air nozzles (the photo car here is wearing optional 22s), and revised software mapping for BMW’s xDrive all-wheel-drive system and the eight-speed automatic transmission. The Alpina badge on the steering wheel (which features push buttons in place of shift paddles), a leather-covered instrument panel with a digital gauge cluster, and custom leather and wood trim are included, too.
The U.S. market is getting an X3 diesel soon enough, but likely it’ll use the same 2.0-liter four-cylinder as in our 328d. Luckily, we can experience a high-powered diesel six, delivering a healthy 261 horsepower and 457 lb-ft, in our 540d sedan.