2015-2018 BMW 6 Series Coupe (F13 LCI facelift ) 640d (313 Hp) xDrive Steptronic

The BMW 6 Series Coupe (F13 LCI), specifically the 640d xDrive Steptronic variant, represents a refined and powerful iteration of BMW’s grand touring coupe. Produced from 2015 to 2018, this facelifted version of the F13 generation brought updated styling, improved technology, and continued the 6 Series’ tradition of blending luxury with performance. The 640d, positioned as a mid-to-high range offering within the 6 Series lineup, catered to buyers seeking a balance between spirited driving and efficient long-distance cruising, particularly in European markets where diesel engines held significant popularity. This model combined a potent inline-six diesel engine with BMW’s xDrive all-wheel-drive system and the Steptronic eight-speed automatic transmission.

Technical Specifications

Powertrain & Engine Architecture

The heart of the 640d xDrive Steptronic is BMW’s N57D30B inline-six diesel engine. This engine, a member of the widely-respected N57 family, utilizes a common-rail direct injection system operating at extremely high pressures to optimize combustion efficiency and reduce emissions. The N57D30B features a sequential twin-turbocharger setup, employing a smaller turbocharger for immediate response at low engine speeds and a larger turbocharger to deliver peak power at higher RPMs. An intercooler further enhances performance by cooling the compressed intake air. The engine produces 313 horsepower at 4400 rpm and a substantial 630 Nm (464.66 lb-ft) of torque between 1500 and 2500 rpm. This broad torque curve is a hallmark of diesel engines and contributes to the 640d’s effortless acceleration and strong mid-range performance. The engine is longitudinally mounted at the front of the vehicle. The Steptronic eight-speed automatic transmission is a crucial component, offering smooth and quick shifts. It features adaptive shift programs that adjust to the driver’s style and driving conditions.

Driving Characteristics

The 640d xDrive Steptronic delivers a driving experience characterized by refined power and confident handling. The abundant torque allows for brisk acceleration in virtually any gear, making overtaking maneuvers easy and safe. While not as overtly sporty as the 640i (petrol) or the higher-performance M6 models, the 640d provides ample power for spirited driving. The xDrive all-wheel-drive system enhances traction and stability, particularly in adverse weather conditions. The eight-speed automatic transmission is well-tuned, providing seamless gear changes and contributing to the car’s overall smoothness. Compared to manual transmission versions (which were less common), the automatic offers greater convenience and ease of use, especially in city traffic. The gear ratios are optimized for both acceleration and fuel efficiency, with a tall eighth gear for relaxed highway cruising.

Equipment & Trim Levels

The 640d xDrive Steptronic typically came well-equipped as standard. Interior features included leather upholstery, power-adjustable seats with memory function, a premium sound system, and BMW’s iDrive infotainment system with a central display screen. Standard safety features included ABS, stability control, multiple airbags, and parking sensors. Optional extras were plentiful, allowing buyers to personalize their vehicles. These included features like adaptive cruise control, a head-up display, a panoramic sunroof, upgraded leather trim, and various driver assistance systems. The dashboard layout was typical of BMW at the time, with a driver-focused design and high-quality materials.

Chassis & Braking

The 6 Series Coupe featured a sophisticated chassis designed to balance comfort and handling. The front suspension utilized a double wishbone setup, while the rear employed an independent multi-link suspension. This configuration provided excellent wheel control and a comfortable ride. The 640d xDrive Steptronic was equipped with disc brakes on all four wheels, providing ample stopping power. ABS (Anti-lock Braking System) was standard, enhancing safety during emergency braking. The steering system was a rack-and-pinion type with electric power assistance, offering precise and responsive steering feel.

Market Reception & Comparison

The 640d xDrive Steptronic was generally well-received by automotive critics. It was praised for its refined engine, comfortable ride, and luxurious interior. The fuel economy was a significant selling point, particularly in Europe, where diesel fuel was often cheaper than gasoline. Compared to the 640i, the 640d offered similar performance with significantly better fuel efficiency. The 650i, with its larger V8 engine, provided more outright power but at the expense of fuel economy. The 640d represented a sweet spot for many buyers, offering a compelling blend of performance, luxury, and efficiency.

Legacy

The N57 engine family, including the N57D30B found in the 640d, has proven to be remarkably durable and reliable. While some early N57 engines experienced issues with timing chain guides, these were largely addressed in later iterations. The 640d xDrive Steptronic remains a desirable used car today, offering a luxurious and capable grand touring experience. Maintenance costs are generally reasonable, although preventative maintenance, such as regular oil changes and timing chain inspections, is crucial to ensure long-term reliability. The combination of a powerful diesel engine, all-wheel drive, and a comfortable interior makes it a compelling option for buyers seeking a refined and practical coupe.