The BMW 640i xDrive Steptronic, part of the F13 LCI (Life Cycle Impulse) facelift generation of the 6 Series Coupe produced from 2015 to 2018, represented a compelling blend of performance, luxury, and all-weather capability. Positioned as a mid-range offering within the 6 Series lineup, it slotted between the entry-level 630i and the high-performance 650i. This variant aimed to provide a refined grand touring experience with a focus on everyday usability, appealing to buyers who desired a powerful and comfortable coupe without the outright sporting focus of the top-tier models.
Technical Specifications
| Brand | BMW |
| Model | 6 Series |
| Generation | 6 Series Coupe (F13 LCI, facelift 2015) |
| Type (Engine) | 640i (320 Hp) xDrive Steptronic |
| Start of production | 2015 |
| End of production | 2018 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 10.9-11.4 l/100 km (21.6 – 20.6 US mpg, 25.9 – 24.8 UK mpg, 9.2 – 8.8 km/l) |
| Fuel consumption (extra urban) | 6.1-6.3 l/100 km (38.6 – 37.3 US mpg, 46.3 – 44.8 UK mpg, 16.4 – 15.9 km/l) |
| Fuel consumption (combined) | 7.9-8.2 l/100 km (29.8 – 28.7 US mpg, 35.8 – 34.4 UK mpg, 12.7 – 12.2 km/l) |
| CO2 emissions | 183-191 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.2 sec |
| Acceleration 0 – 62 mph | 5.2 sec |
| Acceleration 0 – 60 mph | 4.9 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 5.5 kg/Hp, 181.3 Hp/tonne |
| Weight-to-torque ratio | 3.9 kg/Nm, 255 Nm/tonne |
| Power | 320 Hp @ 5800-6000 rpm |
| Power per litre | 107.4 Hp/l |
| Torque | 450 Nm @ 1300-4500 rpm (331.9 lb.-ft. @ 1300-4500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | N55B30A |
| Engine displacement | 2979 cm3 (181.79 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 84 mm (3.31 in.) |
| Piston Stroke | 89.6 mm (3.53 in.) |
| Compression ratio | 10.2:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-power turbo, Intercooler |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Coolant | 9.3 l (9.83 US qt | 8.18 UK qt) |
| Kerb Weight | 1765 kg (3891.16 lbs.) |
| Max. weight | 2265 kg (4993.47 lbs.) |
| Max load | 500 kg (1102.31 lbs.) |
| Trunk (boot) space – minimum | 460 l (16.24 cu. ft.) |
| Fuel tank capacity | 70 l (18.49 US gal | 15.4 UK gal) |
| Max. roof load | 75 kg (165.35 lbs.) |
| Length | 4894 mm (192.68 in.) |
| Width | 1894 mm (74.57 in.) |
| Height | 1369 mm (53.9 in.) |
| Wheelbase | 2855 mm (112.4 in.) |
| Front track | 1600 mm (62.99 in.) |
| Rear (Back) track | 1665 mm (65.55 in.) |
| Ride height (ground clearance) | 124 mm (4.88 in.) |
| Drag coefficient (Cd) | 0.29 |
| Minimum turning circle (turning diameter) | 11.7 m (38.39 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 8 gears, automatic transmission Steptronic |
| Front suspension | Double wishbone |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Disc |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 225/55 R17; 245/45 R18; 275/45 R18; 245/40 R19; 275/35 R19; 245/35 R20; 275/30 R20 |
| Wheel rims size | 8J x 17; 8J x 18; 9J x 18; 8.5J x 19; 9J x 19; 8.5J x 20; 9J x 20 |
INTRODUCTION
The F13 640i xDrive Steptronic, launched in 2015 as part of the LCI refresh, built upon the foundation of the F13 6 Series Coupe introduced in 2011. The LCI brought revised styling, updated technology, and more efficient engine options. This particular variant utilized BMW’s N55B30A inline-six engine paired with an eight-speed Steptronic automatic transmission and the xDrive all-wheel-drive system. It was designed to offer a balance between performance and fuel economy, appealing to buyers who wanted a luxurious and capable grand tourer for all seasons.
Powertrain & Engine Architecture
At the heart of the 640i xDrive was the N55B30A 3.0-liter inline-six engine. This engine was a mainstay of BMW’s lineup for several years, known for its smooth power delivery and responsiveness. It featured direct fuel injection, a twin-scroll turbocharger, and variable valve timing (VANOS) and valve lift (Valvetronic) systems. These technologies worked in concert to optimize power and efficiency across a wide range of engine speeds. The N55 produced 320 horsepower at 5800-6000 rpm and 450 Nm (331.9 lb-ft) of torque between 1300 and 4500 rpm. The eight-speed Steptronic automatic transmission offered smooth and quick shifts, with the ability for the driver to manually select gears using steering wheel-mounted paddles. The xDrive all-wheel-drive system intelligently distributed power between the front and rear axles, enhancing traction and stability, particularly in adverse weather conditions.
Driving Characteristics
The 640i xDrive Steptronic delivered a refined and comfortable driving experience. While not as overtly sporty as the 650i, it offered ample power for confident overtaking and highway cruising. The xDrive system provided excellent grip, inspiring confidence in corners and on slippery surfaces. The eight-speed automatic transmission was well-tuned, providing seamless gear changes and contributing to the car’s overall smoothness. Compared to the six-speed manual transmission available on some 6 Series models, the Steptronic offered greater convenience and ease of use, particularly in urban traffic. However, some enthusiasts found the manual transmission more engaging. The 640i’s power delivery was linear and predictable, making it easy to modulate the throttle and maintain control. Acceleration from 0 to 60 mph took approximately 4.9 seconds, making it a genuinely quick coupe.
Equipment & Trim Levels
The 640i xDrive Steptronic came standard with a generous array of features, including leather upholstery, power-adjustable seats with memory function, a premium sound system, a navigation system, and a rearview camera. Optional extras included features such as adaptive cruise control, a head-up display, a Bang & Olufsen sound system, and various interior trim options. The interior design was characterized by high-quality materials and a driver-focused layout. The dashboard featured a large central display screen, and the controls were logically arranged and easy to use. The standard upholstery was typically Dakota leather, with extended Merino leather available as an option.
Chassis & Braking
The 6 Series Coupe featured a sophisticated chassis design, with a double-wishbone front suspension and an independent multi-link rear suspension. This setup provided a comfortable ride while maintaining good handling characteristics. The 640i xDrive was equipped with disc brakes on all four wheels, providing ample stopping power. The ABS (Anti-lock Braking System) and stability control systems helped to maintain control during emergency braking maneuvers. The steering was precise and well-weighted, providing good feedback to the driver. The xDrive system also played a role in enhancing braking performance by distributing braking force to all four wheels.
Market Reception & Comparison
The 640i xDrive Steptronic was generally well-received by automotive critics. It was praised for its refined driving experience, luxurious interior, and all-weather capability. Compared to the 650i, the 640i offered a more affordable entry point into the 6 Series lineup, while still providing a high level of performance and luxury. Fuel economy was also a strong point for the 640i, with combined fuel consumption figures ranging from 7.9 to 8.2 l/100 km (29.8 – 28.7 US mpg). Compared to the 630i, the 640i offered a significant performance upgrade, making it the more popular choice among buyers who wanted a more engaging driving experience.
Legacy
The N55 engine, found in the 640i xDrive, has proven to be a relatively reliable powertrain. While some early N55 engines experienced issues with the fuel injectors and oil leaks, these problems were largely addressed in later production years. The eight-speed Steptronic automatic transmission is also known for its durability. Today, the F13 640i xDrive Steptronic represents a compelling value on the used car market. It offers a blend of performance, luxury, and all-weather capability that is hard to match in its price range. Well-maintained examples are likely to continue to appreciate in value as they become increasingly sought after by enthusiasts.
