BMW has long offered fine driving cars for every luxury budget, but four-door models have generally been the company's bread and butter. The BMW 6 Series coupe and convertible are for those seeking two-door style in a high-end package that's a bit more extravagant than the norm. The current 6 Series follows in its predecessor's footsteps as a complement to BMW's 5 Series and 7 Series sedans, offering a similar range of six- and eight-cylinder power but adding a unique sense of exclusivity and style.
New or used, the 6 Series siblings rank among the more interesting luxury two-doors on the market. They have their faults, to be sure, and they also face stiff competition from several prestigious competitors. On the other hand, their technology is cutting-edge and their powertrains are superb. It's hard to go wrong with any 6 Series model that fits your budget.
Current BMW 6 Series
The current BMW 6 Series is offered as a coupe and a convertible. The convertible is notable for its clever soft-top roof design with a separately controlled rear window. You can lower that window with the roof up for added ventilation, or raise it as a wind deflector with the roof down.
The base 640i is powered by a turbocharged 3.0-liter inline-6 with 315 horsepower and 332 pound-feet of torque. The 650i steps up to a turbocharged 4.4-liter V8 that cranks out a formidable 445 hp and 480 lb-ft of torque. Rear-wheel drive and an eight-speed automatic transmission are standard on all models, with "xDrive" all-wheel drive optional. And yes, that includes the convertibles -- so if you want a 445-hp drop top with AWD and a fabric roof, BMW will be more than happy to build you one.
Standard features on the 640i include adaptive xenon headlights, adaptive suspension dampers, six-way power heated front seats with lumbar adjustments, leather upholstery, dual-zone automatic climate control and the iDrive electronics interface with a 10.2-inch display and navigation. The 650i adds larger wheels, an upgraded audio system and 16-way power front seats. In typical BMW fashion, the options list is generous and pricey, highlighted by side- and surround-view cameras, self-closing automatic doors, a leather-covered dashboard, adaptive cruise control, a night-vision camera and ceramic-trimmed knobs.
Despite its substantial size, the 6 Series is best for two passengers. The rear compartment is strictly for short trips unless you put a small child back there. However, those up front will be treated to first-class accommodations with very comfortable seats, top-notch materials and high-tech gizmos aplenty. Furthermore, the trunk is rather generous for a luxury sport coupe at 12.3 cubic feet. Even the convertible's trunk measures a decently sized 10.6 cubic feet with the top lowered. Retractable-hardtop convertibles typically hold much less than that with their roofs stowed away.
From behind the wheel, no one will mistake the 6 Series for a 4 Series. This burly grand tourer has few sporting pretensions, though it's far from clumsy and the steering is precise enough to make BMW's biggest two-door feel reasonably spry. Highway runs are where the 6 Series really excels, racking up hundreds of well-insulated, fatigue-free miles at a stretch with effortless passing power -- particularly from the otherworldly V8.
Used BMW 6 Series Models
The current, third-generation 6 Series debuted for 2012 with larger dimensions and more conservative styling than its rather avant-garde predecessor, as well as turbocharged power in place of that model's naturally aspirated engines. It's also the first 6 Series to offer all-wheel drive. The first-year 650i was marginally less powerful (400 hp and 450 lb-ft) and had a manual transmission option, while the 640i models weren't eligible for all-wheel drive until 2014. Changes have otherwise been minimal.
The previous, second-generation BMW 6 Series was produced from 2004-'10 in coupe and convertible body styles. Originally, this 6 Series came equipped with a 4.4-liter V8 rated at 325 hp and 330 lb-ft of torque and was known as the 645Ci. For 2006, the name changed to 650i (minus the "C") and its engine was updated to a 4.8-liter V8 that produced 360 hp and 360 lb-ft of torque. The 645Ci and 650i drive quite similarly -- the smaller V8 shares the 4.8-liter's athletic character but has a slightly less vigorous power delivery. If you find a well-kept 645Ci on the used market, you won't find it lacking from a performance standpoint.
Prior to 2008, the second-generation 6 Series offered three six-speed transmissions: a traditional manual, a traditional automatic and BMW's SMG, which used an electronically controlled clutch to provide both the responsiveness of a manual and the forget-about-it friendliness of an automatic. The SMG may sound tempting, but we'd steer clear, as its herky-jerky performance can make everyday driving a literal pain in the neck. Most 6 Series from this era were equipped with the traditional automatic, but it didn't become standard until 2010. The manual became an option at that point.
Shoppers should note that beyond the powertrain changes, in-car electronics were also upgraded over the years. Early models feature older versions of BMW's iDrive system, which was still in its nascent stages and quite frustrating to use. Gradual improvements were made, but it wasn't until 2010 that the system became fully worthwhile.
In reviews of the second-generation BMW 6 Series, we found that the ride was supple and quiet, the brakes were powerful, and despite nearly 2 tons of weight, handling limits remained high thanks to sophisticated tuning and a well-balanced chassis. Adding the Sport package firmed up the ride and increased cornering grip via a set of 19-inch wheels and tires, while the variable-ratio active steering quickened low-speed turning response.
As with any luxury touring coupe or convertible, the specific mission of this BMW 6 Series was to cover lots of road in a hurry while making its occupants look and feel great -- the front ones, anyway. Unfortunately, the 6 Series offered little of the rear seat space found in its contemporary 5 Series sedan counterpart despite similar midsize dimensions. Also, neither the 650i coupe nor the convertible were considered fashion leaders at the time, though their relative rarity today may make their unconventional lines more appealing.
Not counting the BMW 8 Series of 1990s vintage, the precursor to the modern 6 Series models is the first-generation 6 Series coupe produced from 1977-'89. All models used an inline six-cylinder engine ranging from 3.2 to 3.5 liters, tuned to varying degrees of power. Even the most potent version could only accelerate to 60 mph in the low 6-second range and grip the road in the upper 0.70g range -- modest by modern standards -- while the car's semi-trailing arm rear suspension never did the best job of keeping the car planted to the road. Still, it was an engaging car to drive in its day, and for that reason the original BMW 6 Series coupe retains an important place in BMW history.