The 2009 BMW 650i Convertible represents the pinnacle of luxury open-top motoring, marrying a breathtaking retractable hardtop with a robust and sophisticated powertrain. Under the sculpted hood lies the heart of this grand tourer, a twin-turbocharged 4.4-liter V8 engine that delivers a compelling blend of refined power and effortless performance. This specific model year stands as a testament to BMW's engineering prowess during the final phase of the E63 generation's lifecycle, offering an intoxicating mix of daily usability and weekend exhilaration for discerning buyers.
The Heart of the Machine: The N63B44 Engine
Propelling the 2009 650i Convertible is the legendary BMW N63B44, a 4.4-liter, twin-turbocharged, aluminum V8 that redefined the brand's approach to high-performance engines. Unlike its naturally aspirated predecessors, the N63 introduced forced induction, providing a massive surge in power and torque that was crucial for offsetting the additional weight of the convertible top and chassis reinforcements. This powerplant was a technological marvel in its era, featuring direct injection, continuously variable valve timing (Double-VANOS), and advanced turbocharging technology to deliver a driving experience that was both thrilling and surprisingly tractable.
Powertrain Specifications and Performance
| Specification | Detail |
|---|---|
| Engine Code | N63B44 |
| Configuration | 90-degree V8 |
| Displacement | 4,395 cc (4.4L) |
| Horsepower | 360 hp @ 6,250 rpm |
| Torque | 369 lb-ft @ 1,500 rpm |
| Drivetrain | Rear-wheel drive (xDrive available) |
| Top Speed | 155 mph (electronically limited) |
| 0-60 mph | ~5.2 seconds |
These figures translate into an intoxicating driving experience, where the surge of power arrives late but is immensely satisfying. The engine's true strength lies in its low-end torque; the pair of turbochargers spool up quickly from idle, providing effortless pull from 1,500 rpm and eliminating the need for frantic downshifts. This characteristic makes the 650i a relaxed yet potent cruiser, perfectly suited for both highway cruising and carving through mountain roads.
Refinement and Daily Usability
One of the most remarkable aspects of the 2009 650i Convertible is how seamlessly it blends high-performance credentials with everyday usability. The engine note, while authoritative, is more of a smooth, purposeful growl than a brutal scream, allowing for a civilized conversation inside the meticulously insulated cabin. This refinement is a direct result of BMW’s focus on NVH (Noise, Vibration, and Harshness) suppression, ensuring that the convertibles’ occupants are cocooned in luxury whether the top is up or down.
Features Enhancing the Driving Experience
- Valvetronic Technology: This continuously variable intake valve control system provides seamless throttle response, making the power delivery incredibly linear and enhancing fuel efficiency during partial load conditions.
- Automatic Start-Stop: Depending on market and model specifics, an auto start-stop system helps to mitigate the fuel consumption of the large V8, automatically shutting the engine off at traffic lights to save fuel.
- Premium Fuel Recommended: To maintain optimal performance and prevent knocking, the N63B44 performs best on 91-octane (premium) unleaded gasoline, which helps to preserve its efficiency and power output over the long term.
Considerations for the Modern Buyer
Owning a 2009 BMW 650i Convertible, especially one powered by the N63 engine, is a rewarding experience, but it comes with specific responsibilities inherent to complex European machinery. Prospective buyers should be aware that the turbochargers, while robust, are a component that requires mindful attention over high mileage. Furthermore, the sophisticated electronics and complex hydraulic system for the retractable hardtop necessitate a thorough pre-purchase inspection by a BMW specialist to ensure everything functions correctly and to uncover any latent issues from prior ownership.
Legacy and Lasting Appeal
The 2009 model year represents a sweet spot for the E63 6-Series, as it occurred after significant updates that improved reliability and addressed earlier concerns. The 650i Convertible, in particular, cemented its status as a desirable classic, capturing the exotic allure of a convertible V8 with the practicality of a hardtop. For enthusiasts, the combination of the N63’s distinctive sound, the seamless retracting hardtop, and the coupe-like chassis dynamics ensures that the 2009 650i remains a head-turning statement of automotive excellence that ages remarkably well.
Conclusion: More Than Just a Convertible
Looking back on the 2009 BMW 650i Convertible, it’s clear that the N63B44 engine was more than just a power source; it was a defining element of the car's character. It delivered the performance expected of a BMW M car in terms of acceleration, while simultaneously offering the grand touring comfort and refinement befitting its price tag. For the driver seeking a used luxury convertible that offers a genuine connection to the road and an engine that is a joy to hear and drive, the 2009 650i stands as a benchmark machine that is unlikely to be surpassed by its modern counterparts in terms of raw mechanical appeal.
