The BMW 6 Series Convertible (F12) 650i xDrive Steptronic, produced from 2011 to 2012, represents the high-performance end of the F12 generation 6 Series lineup. Positioned as a luxury grand tourer, it combined a powerful V8 engine with BMW’s xDrive all-wheel-drive system and a sophisticated 8-speed automatic transmission. This variant aimed to deliver exhilarating performance with a comfortable and refined driving experience, appealing to buyers seeking a premium open-top vehicle. It sat at the top of the convertible range, above the 640i models, offering significantly more power and a more luxurious experience.
Technical Specifications
| Brand | BMW |
| Model | 6 Series |
| Generation | 6 Series Convertible (F12) |
| Type | 650i (407 Hp) xDrive Steptronic |
| Start of production | 2011 |
| End of production | 2012 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 16.6 l/100 km (14.2 US mpg, 17 UK mpg, 6 km/l) |
| Fuel consumption (extra urban) | 8.4-8.5 l/100 km (28 – 27.7 US mpg, 33.6 – 33.2 UK mpg, 11.9 – 11.8 km/l) |
| Fuel consumption (combined) | 11.4-11.5 l/100 km (20.6 – 20.5 US mpg, 24.8 – 24.6 UK mpg, 8.8 – 8.7 km/l) |
| CO2 emissions | 266-267 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 4.9 sec |
| Acceleration 0 – 62 mph | 4.9 sec |
| Acceleration 0 – 60 mph | 4.7 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 5 |
| Weight-to-power ratio | 4.9 kg/Hp, 205 Hp/tonne |
| Weight-to-torque ratio | 3.3 kg/Nm, 302.3 Nm/tonne |
| Power | 407 Hp @ 5500-6400 rpm |
| Power per litre | 92.6 Hp/l |
| Torque | 600 Nm @ 1750-4500 rpm (442.54 lb.-ft. @ 1750-4500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | N63B44A |
| Engine displacement | 4395 cm3 (268.2 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 89 mm (3.5 in.) |
| Piston Stroke | 88.3 mm (3.48 in.) |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 9 l (9.51 US qt | 7.92 UK qt) |
| Coolant | 14.6 l (15.43 US qt | 12.85 UK qt) |
| Kerb Weight | 1985 kg (4376.18 lbs.) |
| Max. weight | 2465 kg (5434.39 lbs.) |
| Max load | 480 kg (1058.22 lbs.) |
| Trunk (boot) space – minimum | 300 l (10.59 cu. ft.) |
| Trunk (boot) space – maximum | 350 l (12.36 cu. ft.) |
| Fuel tank capacity | 70 l (18.49 US gal | 15.4 UK gal) |
| Length | 4894 mm (192.68 in.) |
| Width | 1894 mm (74.57 in.) |
| Height | 1365 mm (53.74 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) | 123 mm (4.84 in.) |
| Drag coefficient (Cd) | 0.32 |
| Minimum turning circle | 11.7 m (38.39 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears | 8 |
| Gearbox type | 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 650i xDrive Steptronic is BMW’s N63B44A 4.4-liter twin-turbocharged V8 engine. This engine utilizes direct fuel injection and Valvetronic variable valve timing, contributing to its high power output and relatively good fuel efficiency for its class. The twin turbochargers, positioned within the V of the engine, minimize turbo lag and provide a broad torque curve. The engine produces 407 horsepower at 5,500-6,400 rpm and a substantial 600 Nm (442 lb-ft) of torque between 1,750 and 4,500 rpm. This power is delivered to all four wheels through BMW’s xDrive all-wheel-drive system and an 8-speed Steptronic automatic transmission. The Steptronic transmission offers both fully automatic operation and manual gear selection via steering wheel-mounted paddles, allowing drivers to tailor the driving experience to their preferences.
Driving Characteristics
The 650i xDrive Steptronic delivers a refined yet potent driving experience. The combination of the powerful V8 engine, all-wheel drive, and the 8-speed automatic transmission results in brisk acceleration – 0 to 60 mph in approximately 4.7 seconds. The xDrive system provides excellent traction, particularly in adverse weather conditions, enhancing stability and confidence. While not as overtly sporty as some rear-wheel-drive competitors, the 650i offers a comfortable ride and predictable handling. The automatic transmission is generally smooth and responsive, although some drivers may prefer the more engaging feel of a manual gearbox. Compared to the 640i models, the 650i offers a significant performance advantage, with noticeably quicker acceleration and a more authoritative engine note.
Equipment & Trim Levels
The 650i xDrive Steptronic came standard with a comprehensive list of luxury features, including leather upholstery, power-adjustable heated seats, a premium sound system, navigation, and automatic climate control. Common options included upgraded leather trim, a head-up display, active steering, and various driver-assistance systems such as lane departure warning and adaptive cruise control. The interior design emphasized luxury and comfort, with high-quality materials and a driver-focused layout. The convertible top was fully automatic and could be raised or lowered in around 30 seconds.
Chassis & Braking
The F12 6 Series Convertible featured a sophisticated chassis design with a double-wishbone front suspension and an independent multi-link rear suspension. This setup provided a good balance between ride comfort and handling precision. The 650i xDrive Steptronic was equipped with ventilated disc brakes on all four wheels, providing ample stopping power. The ABS (Anti-lock Braking System) and electronic stability control systems further enhanced safety and control. The steering was electrically assisted, offering precise and responsive feel.
Market Reception & Comparison
The 650i xDrive Steptronic was generally well-received by automotive critics, who praised its powerful engine, luxurious interior, and refined driving experience. However, some reviewers noted that the car’s weight and size could make it feel less agile than some competitors. Fuel economy, while reasonable for a V8-powered convertible, was not a strong point. Compared to the 640i models, the 650i offered a significant performance upgrade but came at a higher price. The xDrive all-wheel-drive system added to the cost but provided enhanced traction and safety, particularly in colder climates.
Legacy
The N63B44A engine, while powerful, has been known to require careful maintenance, particularly regarding cooling system components and turbocharger health. Early versions of the engine were prone to oil leaks and cooling system failures, but these issues were largely addressed in later revisions. Today, well-maintained 650i xDrive Steptronic models can still provide a rewarding driving experience. However, potential buyers should be aware of the potential maintenance costs associated with the engine and transmission. The F12 6 Series Convertible, including the 650i variant, remains a desirable vehicle for those seeking a luxurious and capable grand tourer.
