What is in this article?:
- 2016 Winner: BMW 3.0L Turbocharged DOHC I-6
- Longer Stroke, Bigger Turbo
’s B58 I-6, springing from a new EfficientDynamics modular family of 3-, 4- and 6-cyl. engines, has a larger turbocharger, all-new water-to-air intercooler, longer stroke, more horsepower and torque and several fuel-saving technologies.
If anyone wants to challenge’s stubborn adoration for the inline 6-cyl. architecture, a Bavarian powertrain executive need only cite the final page of the program for the 2016 Wards 10 Best Engines ceremony, to be held Jan. 13 in Detroit.
On that page,reigns as the all-time leader, with 32 trophies since 1995. All but six of those were earned by engines with six pistons marching in single file.
Marching is an apt analogy when describing the inner workings of a BMW I-6, because the silky smoothness, whether marching at double time or in a full-on sprint, suggests a troop of lean, mean fighting machines moving in perfect unison, urging each other to be all they can be.
This year, BMW takes home yet another trophy for the new 340i sedan and its turbocharged I-6, the 3.0L B58, which springs from a new EfficientDynamics modular family of 3-, 4- and 6-cyl. engines used by the BMW and Mini brands.
No matter the cylinder count, each combustion chamber displaces 0.5L, so cutting the 6-pack in half results in a 1.5L 3-cyl. (B38), and lopping off two makes for a 2.0L 4-cyl. (B46 and B48). It’s that simple.
More challenging was deciding which of these three engines belongs on the 2016 list. The B38 3-cyl. earned a trophy in 2015 and returned for test drives this past fall under the hood of the 134-hp Mini Hardtop. It does not find the winner’s circle but makes a favorable impression.
The 228-hp B48 2.0L, evaluated in the Mini John Cooper Works hardtop, scores well and truly was in the hunt. But we opt for one engine to represent the EfficientDynamics family, and the B58 truly is the golden child.
One might suggest BMW engines change very little from one generation to the next, so let’s explore that claim.
The last I-6 turbo was the sublime N55, which earned its 10 Best Engines stars in 2011, 2012 and 2013. Like the new B58, it displaced 3.0L and relied on direct fuel injection, twin-scroll turbocharging, all-aluminum construction, Double-VANOS variable camshaft timing and Valvetronic fully variable valve lift.