2012-2015 BMW 6 Series Convertible (F12) 650i (450 Hp) Steptronic

The BMW 6 Series Convertible (F12) 650i Steptronic, produced from 2012 to 2015, represented the high-performance end of BMW’s luxury convertible range. Positioned as the flagship engine option within the F12 generation, it offered a significant step up in power and refinement compared to the 640i models. Built on the F12 platform, which shared underpinnings with the contemporary 5 Series (F10), the 650i aimed to blend grand touring comfort with engaging performance in an open-top package. This variant catered to buyers seeking a powerful, luxurious, and technologically advanced convertible experience.

Technical Specifications

INTRODUCTION

The F12 650i Steptronic, launched in 2012, was a significant departure from its E63 predecessor, embracing a more sophisticated and technologically advanced approach to the luxury convertible segment. It represented the pinnacle of the F12 6 Series range, offering a blend of performance, luxury, and open-air driving enjoyment. The “Steptronic” designation refers to BMW’s 8-speed automatic transmission, a key component in delivering smooth and efficient power delivery. This model aimed to compete with grand tourers from Porsche, Mercedes-Benz, and Lexus, offering a distinctive BMW driving experience.

Powertrain & Engine Architecture

At the heart of the 650i lies the N63B44B engine, a 4.4-liter twin-turbocharged V8. This engine, a cornerstone of BMW’s performance lineup during this period, utilizes direct fuel injection and variable valve timing (Valvetronic) to optimize power and efficiency. The twin-turbocharger setup, employing twin-scroll technology, minimizes turbo lag and delivers a broad, flat torque curve. The N63 engine is known for its robust construction and ability to handle significant power upgrades. The 8-speed Steptronic automatic transmission is a crucial element, offering both fully automatic operation and manual gear selection via steering wheel-mounted paddles. This transmission is designed for smooth shifts and efficient power transfer, contributing to both performance and fuel economy. Gear ratios are tuned to provide strong acceleration in all gears, while also maintaining comfortable cruising at highway speeds.

Driving Characteristics

The 650i Steptronic delivers a refined yet potent driving experience. The 450 horsepower and 650 lb-ft of torque provide effortless acceleration, with a 0-60 mph time of around 4.4 seconds. The Steptronic transmission contributes to smooth and seamless gear changes, enhancing the overall driving experience. Compared to the 640i models, the 650i offers a significantly more powerful and responsive feel. While the 640i prioritized fuel efficiency and a more balanced driving experience, the 650i focused on delivering exhilarating performance. The weight distribution, optimized by the front-engine, rear-wheel-drive layout, contributes to balanced handling and predictable cornering behavior. The convertible top, while adding some weight, doesn’t significantly detract from the car’s agility.

Equipment & Trim Levels

The 650i Steptronic came standard with a comprehensive array of luxury features, including leather upholstery, power-adjustable seats with memory function, a premium sound system, and a navigation system. Standard exterior features included 19-inch alloy wheels, adaptive xenon headlights, and a power-operated soft top. Optional extras included upgraded leather trim, a Bang & Olufsen sound system, active steering, and a head-up display. Interior trim options allowed for personalization, with choices ranging from wood veneers to aluminum accents. The overall interior design emphasized luxury and sophistication, with a driver-focused cockpit and high-quality materials.

Chassis & Braking

The F12 650i utilizes a double-wishbone front suspension and an independent multi-link rear suspension, providing a comfortable ride and precise handling. The suspension is tuned to balance comfort and performance, offering a compliant ride over uneven surfaces while maintaining body control during spirited driving. Ventilated disc brakes are fitted to all four wheels, providing ample stopping power. Anti-lock braking system (ABS) and dynamic stability control (DSC) are standard features, enhancing safety and stability. The steering system is an electric power-assisted rack-and-pinion setup, offering precise and responsive steering feel.

Market Reception & Comparison

The 650i Steptronic was generally well-received by automotive critics, who praised its powerful engine, luxurious interior, and refined driving experience. However, some critics noted the relatively high price tag and the complexity of the technology. Compared to the 640i, the 650i offered a significant performance advantage but at a higher cost and with slightly lower fuel economy. The 650i also faced competition from other luxury convertibles, such as the Porsche 911 Cabriolet and the Mercedes-Benz SL-Class. The BMW generally offered a more driver-focused experience compared to the more comfort-oriented Mercedes-Benz.

Legacy

The N63B44B engine, while initially prone to some oil consumption issues, has proven to be a durable and reliable powerplant with proper maintenance. The 8-speed Steptronic transmission has also demonstrated good long-term reliability. Today, the F12 650i Steptronic remains a desirable grand tourer, offering a blend of performance, luxury, and open-air driving enjoyment. Used examples are available at a range of prices, depending on mileage, condition, and options. Regular maintenance, including oil changes and inspections of the cooling system, is crucial for ensuring the long-term reliability of this vehicle. The F12 650i represents a high point in BMW’s convertible history, offering a compelling combination of performance and luxury.