Overview:
The 645Ci is available as a coupe or, as tested here, a convertible. 3 Transmissions are available, an automatic, a 6-speed manual or the Sequential Manual Gearbox or SMG. (more on that later) All 6-series cars are powered by a 4.4-liter V8. Precise handling, a powerful engine and a long list of standard performance and luxury items are highlights. Competitors include the Mercedes SL- Class.

Under the Hood:
The powerful DOHC 4.4-liter engine mentioned above produces 325 horsepower and 330 pound feet of torque. Valvetronic variable valve lift, variable valve timing and a variable intake manifold enhance engine breathing. This smooth running engine sweeps the tach needle effortlessly to its 6,500-RPM redline. Acceleration is brisk with a claimed 0-60 time of around 6 seconds. Fuel consumption varies depending on which transmission you choose with the 6-speed automatic achieving the best MPG at 18 city/25 highway. Manual shift 645's are listed next at 17/25 with the SMG estimated at 16/24. I averaged 16.5 with the SMG equipped 645 I drove for this report.

If performance is your priority choose either the manual or the SMG. The 6-speed Steptronic automatic is naturally the best for ease of operation and will likely be the transmission of choice for most buyers. The Sequential Manual Gearbox is also a 6-speed. This clutch-less manual can be shifted with the floor-mounted shifter, with steering wheel mounted paddles or you can let the computer do the work by leaving the indicator in the 'D' position. The instrument panel display places a 'D' before the gear number when in 'Drive' but it's all too easy to forget this when you think you have selected the drive mode.

More than once I thought I was in drive only to discover I was in fact in the manual shift position. The result: unintended engine revving until you either manually select the next gear or push the shifter to the right to select drive. I suspect this is why SMG cars are rated last in fuel economy among the 3 transmission choices. Shifts are generally smooth and predictable but keep in mind that this is a performance transmission. Those desiring a more carefree driving experience will want the smoother Steptronic automatic. .

Ride/ Handling/Hauling:
I am often asked which car I would I select as my personal favorite when it comes to driving satisfaction. The answer is simple: BMW. They are, quite simply, the best handling mass-produced cars on the planet. Add in precise steering and a well-controlled ride and you have a world-beater. The 645Ci is no exception. The car is a joy to drive. The four-wheel independent suspension features aluminum double-pivot struts in front and a 4-link arrangement in the rear. Our test car featured the 'Sport Package', a $2,800 option. With it you get 'Active Steering' which varies the steering ratio with vehicle speed, and 'Active Roll Stabilization' or ARS. This system is designed to reduce body roll by changing the degree of wheel angle relative to the vehicle thereby altering steering geometry. Performance run-flat tires are mounted to 19" alloy wheels. 18" wheels are standard as are Dynamic Stability Control and Traction Control. Braking is excellent with vented discs all around. ABS is, of course, standard along with 'Dynamic Brake Control' and 'Electronic Brake Proportioning'. BMW's website gave no explanation as to how these last two braking systems operate.

On the Inside:
A warm-weather spell in mid May meant that I was able to enjoy top down motoring with the 645 and I loved it! The top opens and closes smoothly and quickly with the touch of a button. Most controls are logically located and the round instrument cluster is straightforward and easy to read at a glance. Interestingly, there is no gauge for coolant temp but there is one for engine oil temperature. Coolant temp can be selected with the I-drive menu. It's in there somewhere. Speaking of which, I've never been a fan of idrive, the round knob that navigates you through a maze of menus as you divert your eyes from the road to a dash mounted screen to select 'Entertainment', 'Navigation' and the like. For the most part it works OK (I guess) except when you get into the audio controls. Changing radio stations involves a series of pushing and turning of the idrive knob as you select between AM, FM and CD. I'll let you decide if this sounds luxurious or needlessly complex. BMW did have the good sense to include a knob for volume. The steering wheel also features controls for audio and cell phone for hands on driving.

Our 645Ci had the optional Logic 7 audio system pumping 315 watts of two-channel sound through 13 speakers. A 7-channel playback matrix creates 360-degree surround sound in the cabin. As you would expect, audio quality is outstanding. An excellent navigation system is standard on all 645's. Automatic climate control is operated with simple to use knobs logically located on the lower dash.

It's easy to find a comfortable driving position thanks to a power tilt and telescopic steering column and power front seats. Legroom is plentiful up front and the sport seats are super comfortable with excellent support for spirited driving. Forward visibility is very good for the front passengers. Drivers will want to use the heated power mirrors with the top up. Another convertible trait. The interior features rich materials and top notch build quality, typical BMW. One thing I didn't like was the turn signal stalk. It does not 'click' when you move it into position and there is no sound so it's hard to tell when it's on. Eventually a beep will sound off telling you that it's been left on. I don't get the thinking with this set-up. A small thing but it bugged me.

Safety/Warranty:
Dual threshold 'smart' airbags are provided for driver and passenger along with floor-mounted side impact bags. Park distance control alerts the driver to obstacles both ahead and behind the car. Great for parking. Xenon headlights are auto leveling and feature a high pressure washing system. Halogen fog lights are included. BMW warrants the 645Ci for 4 years or 50K miles.

Bottom Line:
This may be the longest car review I have ever written. There is much to say about this fine automobile, and almost all of it is good. I'm still not a fan of idrive but it did not seem as bad as the last time I used it (in a 7 series). Maybe I'm getting used to it. In any case, it wouldn't stop me from recommending this car. I would not recommend the SMG transmission to most people. No doubt some will love it. Drive before you decide. One last thing: The optional 19" tires ride a little rougher than the standard 18 wheels. For many, the standard wheel package will still provide great handling and a smooth ride. If you love to drive you can never go wrong with a BMW.

Tom Collins
05/25/05