In a world where the hum of electric motors is becoming the new norm, the classic diesel engine has seen its market share in Europe dip to roughly 6.6 percent. It is a stark contrast to a decade ago when diesels dominated more than half of the industry. However, while many manufacturers are retreating from the "oil-burner," BMW is choosing to stand its ground. Staying true to its "Power of Choice" philosophy, the Munich-based brand is continuing to offer diesel options across its entire fleet, from the agile 1 Series to the palatial X7. The latest proof of this commitment is the newly refined 740d xDrive. Rather than phasing out the flagship diesel, BMW engineers have spent months under the hood of the legendary "B57" 3.0-liter inline-six. By integrating a sophisticated 48-volt mild-hybrid system directly into the eight-speed automatic transmission, they have managed to boost output to 308 horsepower. While a tenth of a second off a sprint time might not b...