BMW 640i Convertible: Complete Grand Tourer Review

The BMW 640i Convertible stands out as a premium open-top vehicle designed for those who crave a mix of exhilarating performance and effortless long-distance comfort. Powered by a turbocharged 3.0-liter inline-six engine producing 315-316 horsepower and up to 330 lb-ft of torque, it delivers smooth acceleration with a 0-60 mph time around 4.9 to 5.7 seconds, depending on testing conditions. This model occupies a unique niche, bridging muscle car affordability and high-end luxury without direct rivals in its price range.

Engine Performance and Power Delivery

At the heart of the BMW 640i Convertible is its refined turbocharged straight-six engine. This powerplant generates peak torque from as low as 1,300 rpm, providing consistent thrust up to 4,500 rpm, paired seamlessly with an eight-speed automatic transmission. The ZF unit shifts smoothly, whether via paddle shifters or the electronic selector, enabling a quarter-mile run in about 13.6 seconds.

Reviewers note the engine’s willingness to rev, offering fizzy top-end power despite a slight lag at very low speeds. In real-world driving, it feels potent for overtaking and highway merging, though heavier competitors like the Mercedes SL400 edge it slightly in sprint times due to better power-to-weight ratios. Fuel economy hovers around 35.8 mpg combined, with CO2 emissions at 185 g/km, making it relatively efficient for its class.

• Peak Power: 315-316 bhp
• Torque: 330-450 Nm (varies by source)
• 0-62 mph: 5.5-5.7 seconds
• Top Speed: Electronically limited to 155 mph
• Transmission: 8-speed automatic, rear-wheel drive

Chassis Dynamics and Handling Precision

The 640i Convertible benefits from BMW’s engineering prowess, including a 50% stiffer chassis than its predecessor, minimizing shakes and rattles even over rough surfaces. Standard adjustable modes—Comfort, Normal, Sport, and Sport+—alter suspension, throttle, steering, and gearbox behavior, transforming it from a plush cruiser to a more engaging handler.

With the optional £3,400 Adaptive Drive system, body roll is virtually eliminated in corners, and stability control allows controlled wheel slip for spirited driving. The £1,220 Integral Active Steering further enhances agility by steering rear wheels, making the car easier to place on twisty roads. On the skidpad, it achieves 0.86 g of grip on summer tires, competitive for a grand tourer weighing over two tons. Everyday pothole absorption rivals the BMW 5 Series, with precise steering feedback.

Design and Exterior Styling

BMW’s design shift toward conservatism yields a sleeker, more proportionate silhouette compared to bolder predecessors. The long hood, short deck, and swept-back lines evoke a classic American cruiser with European flair, ideal for coastal drives or sunny boulevards. The power-folding fabric roof operates smoothly, though slightly slower than some rivals, and maintains excellent sound insulation when up, keeping the cabin hushed.

Wind buffeting is minimal with the top down, thanks to aerodynamic tweaks. M Sport packages add visual sportiness with larger alloys and aggressive styling, though some critics call it faux-athletic on such a heavy machine. At around £65,680 starting price, it undercuts Jaguar XK and Mercedes SL rivals.

Interior Comfort and Practicality

Inside, the 640i Convertible boasts BMW’s finest leather-trimmed cabin, with a sweeping dashboard optionally wrapped in hide, diverting attention from shared 5 Series controls. Headroom suffices for four adults, but rear legroom is tight, prioritizing front passengers. Boot space offers 300-350 liters with the roof up, adequate for weekend getaways.

Refinement shines: superior noise isolation over competitors like the Jaguar XK, and a comfy ride that soaks up bumps without feeling squidgy. Options like head-up display (£980) and 19-inch wheels (£1,290) enhance the experience, though the ride can turn harsh on poor roads.

Technology and Driver Aids

Advanced features include adjustable damping, integral steering, and an intuitive eight-speed auto that anticipates driver inputs. Infotainment, while not detailed in all reviews, integrates seamlessly in later models, with paddle shifters for manual control. Safety systems rein in stability progressively, allowing fun without excess intervention.

Market Positioning and Rivals

Priced between muscle cars like Ford Mustang and premium drop-tops like Bentley, the 640i lacks direct peers. It trails V8 rivals like the 650i by mere tenths in acceleration but offers better efficiency. Against Mercedes SL400, it’s slower but lighter on the wallet; versus Jaguar XK, it’s quieter and more composed.

Pros and Cons Overview

• Pros: Potent turbo engine, versatile drive modes, refined ride, premium interior, strong value vs. rivals.
• Cons: Heavy weight hampers agility, tight rear space, optional extras add up, ride can jar on rough roads.

Ownership Considerations

Long-term ownership reveals a reliable powertrain, though maintenance costs align with luxury norms. The turbo six proves durable, with good residuals for a convertible. Ideal for sunny-day oligarchs or coastal cruisers seeking presence without ostentation.

Frequently Asked Questions (FAQs)

Is the BMW 640i Convertible reliable?

Yes, the turbocharged inline-six is praised for durability, with owners reporting solid performance over 10 years. Regular servicing maintains its excellence.

How fuel-efficient is it?

Expect 35.8 mpg combined, competitive for a powerful grand tourer.

What’s the boot space like?

300-350 liters with roof up, sufficient for light luggage.

Can it handle spirited driving?

Absolutely, Sport+ mode and active steering make it surprisingly capable.

Is it worth the options list?

Adaptive Drive and Integral Steering significantly enhance dynamics, recommended for enthusiasts.