The BMW 6 Series Gran Coupe (F06 LCI), specifically the 640i xDrive Steptronic model, represents a compelling blend of luxury, performance, and practicality within the BMW lineup. Produced from 2015 to 2018, this facelifted version of the F06 Gran Coupe aimed to refine the original model with updated styling, improved technology, and enhanced efficiency. Positioned as a mid-to-high range offering within the 6 Series Gran Coupe family, the 640i xDrive Steptronic catered to buyers seeking a powerful and sophisticated grand tourer with all-weather capability. It sat above the 630i and 633i models, but below the range-topping 650i and M6 variants.
Technical Specifications
| Brand | BMW |
| Model | 6 Series |
| Generation | 6 Series Gran Coupe (F06 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 | 5 |
| Doors | 4 |
| Fuel consumption (economy) – urban | 11.0-11.5 l/100 km (21.4 – 20.5 US mpg) |
| Fuel consumption (economy) – extra urban | 6.1-6.3 l/100 km (38.6 – 37.3 US mpg) |
| Fuel consumption (economy) – combined | 7.9-8.2 l/100 km (29.8 – 28.7 US mpg) |
| CO2 emissions | 184-192 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.3 sec |
| Acceleration 0 – 62 mph | 5.3 sec |
| Acceleration 0 – 60 mph | 5 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 5.7 kg/Hp, 175.3 Hp/tonne |
| Weight-to-torque ratio | 4.1 kg/Nm, 246.6 Nm/tonne |
| Power | 320 Hp @ 5800-6000 rpm |
| 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 | 1825 kg (4023.44 lbs.) |
| Max. weight | 2430 kg (5357.23 lbs.) |
| Max load | 605 kg (1333.8 lbs.) |
| Trunk (boot) space – minimum | 460 l (16.24 cu. ft.) |
| Trunk (boot) space – maximum | 1265 l (44.67 cu. ft.) |
| Fuel tank capacity | 70 l (18.49 US gal | 15.4 UK gal) |
| Max. roof load | 75 kg (165.35 lbs.) |
| Permitted trailer load with brakes (12%) | 290 kg (639.34 lbs.) |
| Length | 5007 mm (197.13 in.) |
| Width | 1894 mm (74.57 in.) |
| Height | 1392 mm (54.8 in.) |
| Wheelbase | 2968 mm (116.85 in.) |
| Front track | 1600 mm (62.99 in.) |
| Rear (Back) track | 1665 mm (65.55 in.) |
| Ride height (ground clearance) | 126 mm (4.96 in.) |
| Drag coefficient (Cd) | 0.29 |
| Minimum turning circle (turning diameter) | 11.95 m (39.21 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 F06 BMW 6 Series Gran Coupe, launched in 2012, aimed to offer a more practical and stylish alternative to traditional two-door coupes. The LCI (Life Cycle Impulse) facelift in 2015 brought subtle but significant updates to the exterior styling, interior refinement, and powertrain options. The 640i xDrive Steptronic, powered by the N55B30A engine, was a key component of this revised lineup. It combined a potent inline-six engine with BMW’s xDrive all-wheel-drive system and the smooth-shifting Steptronic eight-speed automatic transmission, creating a capable and comfortable grand touring machine.
Powertrain & Engine Architecture
At the heart of the 640i xDrive Steptronic lies the N55B30A 3.0-liter inline-six engine. This engine is a direct-injection, twin-turbocharged unit, renowned for its responsiveness and power delivery. The N55 engine family is known for its robust construction and relatively straightforward maintenance. The twin-turbo setup utilizes a single twin-scroll turbocharger, providing minimal turbo lag and a broad torque curve. The engine produces 320 horsepower at 5800-6000 rpm and 450 Nm (331.9 lb-ft) of torque between 1300 and 4500 rpm. This power is then channeled through BMW’s xDrive all-wheel-drive system, which intelligently distributes torque between the front and rear axles for optimal traction. The Steptronic eight-speed automatic transmission offers smooth and quick gear changes, with the ability to manually shift using steering wheel-mounted paddles. The transmission’s gear ratios are tuned for a balance of performance and fuel efficiency.
Driving Characteristics
The 640i xDrive Steptronic delivers a refined and engaging driving experience. The combination of the powerful inline-six engine, all-wheel drive, and eight-speed automatic transmission results in brisk acceleration – 0 to 60 mph in approximately 5 seconds. While not as overtly sporty as the 650i or M6, the 640i offers ample power for confident overtaking and highway cruising. The xDrive system provides enhanced stability and grip, particularly in adverse weather conditions. The Steptronic transmission contributes to a smooth and effortless driving experience, seamlessly shifting gears to keep the engine in its optimal power band. Compared to the manual transmission options available in other 6 Series models, the automatic prioritizes comfort and ease of use, making it ideal for long-distance journeys.
Equipment & Trim Levels
The 640i xDrive Steptronic came standard with a comprehensive array of luxury features. These included leather upholstery, power-adjustable front seats with memory function, a premium sound system, a navigation system, and a rearview camera. Standard safety features included anti-lock brakes, stability control, and a suite of airbags. Optional extras included features such as a head-up display, adaptive cruise control, a panoramic sunroof, and upgraded interior trim options. The interior design emphasized luxury and sophistication, with high-quality materials and a driver-focused layout.
Chassis & Braking
The 6 Series Gran Coupe featured a sophisticated chassis design, incorporating a double-wishbone front suspension and an independent multi-link rear suspension. This setup provided a comfortable ride while maintaining precise handling. The 640i xDrive Steptronic was equipped with disc brakes on all four wheels, providing ample stopping power. The ABS (Anti-lock Braking System) and stability control systems further enhanced safety. The steering system was an electric power-assisted rack and pinion setup, offering precise and responsive steering feel.
Market Reception & Comparison
The 640i xDrive Steptronic was generally well-received by automotive critics. It was praised for its powerful engine, comfortable ride, and luxurious interior. However, some reviewers noted that it lacked the outright sporting character of the 650i and M6 models. Compared to the 633i, the 640i offered a significant performance upgrade. Fuel economy was respectable for a vehicle of its size and performance, averaging around 29.8-28.7 US mpg in combined driving. Reliability was generally good, although some owners reported minor issues with the electronic systems.
Legacy
The BMW 6 Series Gran Coupe (F06 LCI) 640i xDrive Steptronic remains a desirable used car option for buyers seeking a luxurious and capable grand tourer. The N55 engine is known for its durability and relatively low maintenance costs. While not as collectible as the higher-performance 650i or M6 models, the 640i offers a compelling blend of performance, comfort, and value. Its all-wheel-drive system and automatic transmission make it a practical choice for year-round driving, and its stylish design continues to turn heads.
