The BMW 6 Series Convertible (F12) 650i xDrive Steptronic, produced from 2012 to 2015, represents the high-performance end of the F12 6 Series range. Positioned as the flagship convertible before the introduction of the M6 variant, the 650i combined a powerful twin-turbocharged V8 engine with BMW’s xDrive all-wheel-drive system and a sophisticated 8-speed Steptronic automatic transmission. It aimed to deliver a luxurious grand touring experience with impressive performance capabilities, competing with vehicles like the Porsche 911 Cabriolet and Mercedes-Benz SL-Class.
Technical Specifications
| Brand | BMW |
| Model | 6 Series |
| Generation | 6 Series Convertible (F12) |
| Type | 650i (450 Hp) xDrive Steptronic |
| Start of production | 2012 |
| End of production | 2015 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 13.0-13.3 l/100 km (18.1 – 17.7 US mpg, 21.7 – 21.2 UK mpg, 7.7 – 7.5 km/l) |
| Fuel consumption (extra urban) | 7.2-7.3 l/100 km (32.7 – 32.2 US mpg, 39.2 – 38.7 UK mpg, 13.9 – 13.7 km/l) |
| Fuel consumption (combined) | 9.3-9.5 l/100 km (25.3 – 24.8 US mpg, 30.4 – 29.7 UK mpg, 10.8 – 10.5 km/l) |
| CO2 emissions | 217-221 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 4.5 sec |
| Acceleration 0 – 62 mph | 4.5 sec |
| Acceleration 0 – 60 mph | 4.3 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 5 |
| Weight-to-power ratio | 4.4 kg/Hp, 227.3 Hp/tonne |
| Weight-to-torque ratio | 3 kg/Nm, 328.3 Nm/tonne |
| Power | 450 Hp @ 5500 rpm |
| Power per litre | 102.4 Hp/l |
| Torque | 650 Nm @ 2000-4500 rpm (479.42 lb.-ft. @ 2000-4500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | N63B44B |
| 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 | Twin-power turbo, Intercooler |
| Engine oil capacity | 9 l (9.51 US qt | 7.92 UK qt) |
| Coolant | 10.9 l (11.52 US qt | 9.59 UK qt) |
| Kerb Weight | 1980 kg (4365.15 lbs.) |
| Max. weight | 2480 kg (5467.46 lbs.) |
| Max load | 500 kg (1102.31 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 is BMW’s N63B44B engine, a 4.4-liter twin-turbocharged V8. This engine utilizes direct fuel injection and Valvetronic variable valve timing, contributing to both power and efficiency. The twin-turbochargers are positioned within the V-shaped engine bank, promoting quicker response and reduced turbo lag. The engine produces 450 horsepower at 5,500 rpm and a substantial 650 Nm (479 lb-ft) of torque between 2,000 and 4,500 rpm. This broad torque curve is a key characteristic of the N63 engine. The engine is longitudinally mounted at the front of the vehicle.
Power is transmitted to all four wheels via 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. The transmission is tuned for smooth shifts and quick response, complementing the engine’s power delivery. The xDrive system is primarily rear-biased, providing a sporty driving feel while maintaining all-weather traction.
Driving Characteristics
The 650i xDrive Steptronic delivers a refined and powerful driving experience. The combination of the twin-turbo V8 and the all-wheel-drive system results in brisk acceleration – 0 to 60 mph in approximately 4.3 seconds. The broad torque curve ensures strong pull throughout the rev range, making overtaking effortless. While not as overtly sporty as the M6, the 650i offers a compelling blend of performance and comfort. The automatic transmission generally selects the appropriate gear for the driving situation, but manual gear selection via the paddles allows for greater driver control. The xDrive system provides excellent grip in various conditions, enhancing stability and confidence.
Equipment & Trim Levels
The 650i typically came well-equipped as standard. Common features included leather upholstery, power-adjustable and heated front seats, a premium sound system, navigation, and a retractable hardtop. Optional extras included upgraded leather, ventilated front seats, a head-up display, active steering, and various driver-assistance systems like lane departure warning and adaptive cruise control. Interior trim options ranged from wood veneers to aluminum accents, allowing for a degree of personalization.
Chassis & Braking
The F12 6 Series Convertible features a double-wishbone front suspension and an independent multi-link rear suspension. This setup provides a comfortable ride while maintaining good handling characteristics. The 650i typically came equipped with larger brakes than the lower-trim models, featuring ventilated discs at all four corners. ABS (Anti-lock Braking System) and electronic stability control are standard safety features. The steering is electrically assisted, providing precise and responsive control.
Market Reception & Comparison
The 650i xDrive Steptronic was generally well-received by automotive critics. It was praised for its powerful engine, luxurious interior, and refined driving experience. However, some critics noted that the car’s weight could detract from its agility. Compared to the 640i, the 650i offered significantly more power and performance, but at a higher price point. The 650i’s fuel economy was reasonable for a high-performance V8, but it was still considerably lower than that of the 640i. Reliability reports suggest that the N63 engine, while powerful, can be prone to certain issues, such as oil leaks and cooling system problems, requiring diligent maintenance.
Legacy
The F12 650i xDrive Steptronic remains a desirable grand tourer in the used car market. Its combination of performance, luxury, and all-weather capability continues to appeal to enthusiasts. However, potential buyers should be aware of the potential maintenance costs associated with the N63 engine. Regular servicing and preventative maintenance are crucial to ensure the long-term reliability of this powerful and sophisticated vehicle. The F12 generation 6 Series, including the 650i, represents a high point in BMW’s convertible design and engineering.
