BMW M Line Up For 2002 - New Cars 2002

Regular readers of this magazine hardly need to be convinced of the coolness and desirability of BMW's current M cars-they are collectively among the most praised automobiles in existence. Last year, the M5 soldiered on as the ultimate sport sedan with its 396-bhp V8. No other maker offers a car that can really compete with it, for any price.

When we finally got an E46 M3, it was better looking, faster and more pleasant to drive than we imagined it would be, with an all-new 8000-rpm, 333-bhp, 3.4-liter six. In Laguna Seca Blue, it pegged car guys' freak-out meters wherever we went. Then the convertible version arrived, the better for those who care to be seen.

The Z3-based cars, Roadster and Coupe, were transformed and rejuvenated by the new six-cylinder S54 engine. With a more restrictive exhaust than in the M3, they made only 315 bhp, but the Coupe, in particular, makes all the right noises. Porsche fans wondering where the 911's raw, sportingly hard edge went would be advised to look into an M Coupe. Perhaps only an Italian company's current production, at three times the price or more, can match it for its visceral appeal. Together, the M cars form a complete line of performance cars in small, medium and large sizes. Each will more than hold its own against more expensive competition. Each lives up to BMW's slogan.

BMW's engineers have been busy for 2002 with other cars. There is a new 7 Series, with two new V8s and a V12. There is the Mini Cooper and Cooper S. Prototypes of a Z3 replacement were in the paint shop in Spartanburg in early December 2001 when ec toured the plant in conjunction with the launch of a new High Output X5. To top it off, the 3 Series, after just 3 years, has received fresh front and rear treatments. With all this and so much new in 2001 for the M lineup, it would have been excusable if the M cars had been left alone this year. But they were not.

The letters SMG probably carry meaning only to the most ardent of American Bimmerphiles, but they are destined for legend. The rest of us are likely to catch up when we hear Sequential Manual Gearbox. Several years ago, Vinnie Donizetti arrived at the office all ecstatic from having just driven a sequential-shift M3. That was merely a teaser, though, as the E36 M3 SMG, beginning in 1996, was for Europe only. While Japanese companies still keep their highest performance cars at home, European marques are becoming more committed to ensuring that their largest market has access to their finest wares. SMG II will be in the U.S. in 2002.

SMG is not a sequential shift in the mechanical, dog-engagement, race-only sense. Rather, it is similar in concept to Ferrari's F1 paddle shift. In an M3 with SMG, there is no clutch pedal. There is a shift lever on the console and paddles on the steering wheel, but they are merely electrical switches. The complex dance of throttle, clutch and gear selection is carried out by a computer-controlled electrohydraulic system added to an otherwise unchanged conventional gearbox, clutch and the car's drive-by-wire throttle system. The M3's six-speed is the same unit used in the M5, so it is more than adequate for the task.

There are two basic modes of operation: sequential and automated. In sequential mode, the timing of each shift is under the full control of the driver. Moving the lever rearward or actuating the right-hand paddle on the steering wheel effects upshifts; downshifts are executed by pushing the lever forward or actuating the left-hand paddle. There are six programs for the "aggressiveness" of the shifts, controlled by a switch ahead of the shift lever and indicated by a display in the instrument cluster. In S1-5, a higher number indicates a faster shift. In any program, shifts are accomplished faster at higher engine speeds. Dynamic Stability Control must be deactivated to select S6. The minimum shift time is 0.080 sec. versus 2 to 4 times that for the "slowest" (S1) shift program under equal conditions. Try pushing the start/stop button on a stopwatch that quickly-it's unlikely you can shift faster. In sequential mode, activating the shift lever or paddle moves the transmission up or down one gear; multiple gears require multiple actuations.

In SMG's automated mode (BMW calls it DRIVE-LOGIC), there are five programs. As with S, the higher the program number the faster the shift. However, the speeds at which both upshifts and downshifts occur are higher. As well, a wider throttle opening will be met with higher engine speed before shifting. BMW claims the A5 setting is fully sporting and racetrack-ready-just automated.

Several fine points are well thought out. If the M3 comes to a stop in S, SMG will automatically select first gear to start moving again. In A1, however, second gear is used for starting off, making it useful for winter driving. In S mode, if a downshift that would overspeed the engine is requested, it is ignored. In both modes, engine speed and clutch engagement are regulated during downshifts to prevent a loss of traction at the rear wheels, monitored 100 times per second by the DSC system. Uphill and downhill conditions are detected in both modes and used to further optimize the shift programs for the driving at hand.

Besides Ferrari, Toyota also supplies a similar system, which it calls sequential manual transmission, to the U.S. market but not as a performance option. It was originally engineered as a cost-saving and more efficient alternative to an automatic for the economical European Yaris (think Echo). SMT provides a clutchless shift option for the MR2 Spyder, which could not physically accommodate Toyota's larger automatic transmissions. It has only one level of "aggressiveness." To ensure longevity, it is tuned so that a skilled driver can beat it with a conventional shifter.

Any of these electrohydraulically shifted manual transmission systems is superior to a manually shifted automatic because they maintain a solid mechanical link between the engine and the driven wheels, giving direct, instantaneous control of the torque at the wheels and "minor" related functions such as the balance of the chassis in a turn. Furthermore, they aren't wasting energy in a torque converter, so they won't overheat and degrade performance when driven hard.

With eleven possible settings, BMW SMG has more modes of operation than either of its competitors (Ferrari's has only four, Toyota's the one). The Ferrari's paddles are on the steering column rather than on the steering wheel itself, so they may be in an inconvenient location unless one is going straight. Toyota has buttons on the steering wheel, an artifact of manumatic technology throughout its line but, as mentioned earlier, SMT is not a sporting system.

Certainly, there will be some poseurs who drive an M3 with SMG and don't remark on the fact that there are only two pedals. Most of the editors here at ec will agree that these people don't deserve the car. Shifting is an important skill and one that any serious driver should have mastered. However, when driving such a high-performance car as the M3, many excellent drivers wouldn't mind being able to devote more attention to placing the car correctly on the road or racetrack. Racing drivers want any speed advantage that is to be had, and SMG definitely is one. Also, because M cars are real street cars, not just wanna-be race cars, people do tend to drive them to work and sit in traffic. SMG eliminates the choice between compromising the sporting nature of the car with an automatic (which BMW has wisely not done) and looking after the high-strung S54 in stop-and-go traffic. One can both eat and have a more delicious cake than was previously available.

It is this inexorable progression toward perfection that has made M what it is today, and what will continue to drive its greatness in the future.

Chronicle of an SMG Shift

SMG does all the same actions done by a driver shifting a conventional manual transmission. Here's the operating sequence:
1. Via a position sensor, the control system always "knows" which gear is currently engaged.
2. When the driver signals a shift, the system selects the appropriate valves.4. The M3's six individual, electronically controlled throttles are closed.
5. Hydraulic cylinders move the transmission's gearsets into the next gear.
6. If it's a downshift, the engine is revved to the speed it will reach when the selected lower gear is engaged.
7. The clutch is re-engaged.
8. The throttles are opened again.