The BMW 6 Series Coupe (F13) 640i Steptronic, produced from 2011 to 2015, represented a sophisticated blend of performance and luxury within the BMW lineup. Positioned as a mid-range offering in the F13 generation, it slotted between the entry-level 630i (not widely available in all markets) and the high-performance 650i. This variant aimed to deliver a compelling grand touring experience, balancing power with relative efficiency and comfort. The F13 6 Series, as a whole, was BMW’s attempt to recapture the spirit of the original 6 Series coupes of the 1970s and 80s, offering a more driver-focused alternative to the 7 Series sedan.
Technical Specifications
| Brand | BMW |
| Model | 6 Series |
| Generation | 6 Series Coupe (F13) |
| Type (Engine) | 640i (320 Hp) Steptronic |
| Start of production | 2011 |
| End of production | 2015 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 10.3-10.5 l/100 km (22.8 – 22.4 US mpg) |
| Fuel consumption (extra urban) | 6.0-6.2 l/100 km (39.2 – 37.9 US mpg) |
| Fuel consumption (combined) | 7.6-7.8 l/100 km (30.9 – 30.2 US mpg) |
| CO2 emissions | 177-181 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.4 sec |
| Acceleration 0 – 62 mph | 5.4 sec |
| Acceleration 0 – 60 mph | 5.1 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 5 |
| Weight-to-power ratio | 5.2 kg/Hp |
| Weight-to-torque ratio | 3.7 kg/Nm |
| 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 | 1660 kg (3659.67 lbs.) |
| Max. weight | 2180 kg (4806.08 lbs.) |
| Max load | 520 kg (1146.4 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 | 1396 mm (54.96 in.) |
| Wheelbase | 2855 mm (112.4 in.) |
| Front track | 1600 mm (62.99 in.) |
| Rear (Back) track | 1657 mm (65.24 in.) |
| Ride height (ground clearance) | 124 mm (4.88 in.) |
| Drag coefficient (Cd) | 0.30 |
| Minimum turning circle | 11.7 m (38.39 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 8 gears, automatic transmission Steptronic |
| Front suspension | Double wishbone |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| 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 |
Powertrain & Engine Architecture
The heart of the 640i Steptronic is BMW’s N55B30A inline-six engine. This 3.0-liter engine utilizes direct fuel injection and a single twin-scroll turbocharger, producing 320 horsepower and 331 lb-ft of torque. The N55 engine was a significant evolution of BMW’s inline-six tradition, known for its smooth power delivery and responsiveness. The engine’s aluminum block and head contribute to its relatively lightweight construction. The Steptronic transmission is an 8-speed automatic, offering both fully automatic operation and manual shift control via steering wheel-mounted paddles. This transmission is characterized by its quick and smooth shifts, contributing to both performance and efficiency. The transmission’s wide gear ratio spread allows for both strong acceleration and relaxed highway cruising.
Driving Characteristics
The 640i Steptronic delivers a refined and capable driving experience. While not as overtly aggressive as the 650i, the 640i provides ample power for spirited driving. The 0-60 mph time of around 5.1 seconds is respectable, and the engine’s broad torque curve ensures strong acceleration in most situations. The 8-speed automatic transmission is a key component of the driving experience, providing seamless gear changes and contributing to the car’s overall smoothness. Compared to a manual transmission-equipped 640i, the Steptronic version prioritizes ease of use and comfort over outright driver engagement. However, the paddle shifters allow for a degree of control when desired. The rear-wheel-drive configuration provides a balanced feel, although traction can be a concern in wet or slippery conditions.
Equipment & Trim Levels
The 640i Steptronic came standard with a generous array of features, including leather upholstery, power-adjustable seats, a premium sound system, and BMW’s iDrive infotainment system. Common options included a navigation system, a head-up display, adaptive cruise control, and upgraded interior trim materials. The interior design emphasized luxury and sophistication, with high-quality materials and a driver-focused layout. Exterior styling cues included BMW’s signature kidney grille, sleek headlights, and a long, sculpted hood. The 640i could be further customized with various wheel designs and exterior color options.
Chassis & Braking
The F13 6 Series features a sophisticated chassis design, with a double-wishbone front suspension and an independent multi-link rear suspension. This setup provides a comfortable ride while maintaining precise handling. The 640i typically came equipped with ventilated disc brakes on all four wheels, providing ample stopping power. ABS (Anti-lock Braking System) and electronic stability control are standard safety features. The steering is electrically assisted, offering a responsive and precise feel. The car’s weight distribution is well-balanced, contributing to its neutral handling characteristics.
Market Reception & Comparison
The 640i Steptronic was generally well-received by automotive critics, who praised its blend of performance, luxury, and refinement. It was often seen as a more sensible alternative to the more expensive and powerful 650i. Fuel economy was considered good for a vehicle in this class, and the 8-speed automatic transmission was lauded for its smoothness and efficiency. Compared to the 650i, the 640i offered a slightly firmer ride and less outright acceleration, but it also came with a lower price tag and potentially lower maintenance costs. The 640i also offered a more balanced driving experience than the larger and heavier 7 Series sedan.
Legacy
The N55 engine, found in the 640i, has proven to be a relatively reliable powerplant, although preventative maintenance is crucial. Common issues include oil leaks, fuel injector problems, and occasional turbocharger failures. The 8-speed Steptronic transmission is also generally reliable, but regular fluid changes are essential. Today, the F13 640i Steptronic represents a compelling value on the used car market, offering a luxurious and capable grand touring experience at a relatively affordable price. Its combination of performance, comfort, and technology continues to appeal to enthusiasts seeking a sophisticated and rewarding driving experience.
