Whenever
we talk about sports
saloon, M5 is always the first label we would think of. Since its birth
in
1984, it has been recognized as the benchmark of sports saloon. M5 was
not the
first sports saloon, but it successfully turned sports saloons from
special
editions to a sustainable business case. From E28 to the latest E60 M5,
4
generations ran almost non-stop during the past 20 years. It is the
purest
bloodline in the sports saloon world.M535i E12 (1979-81) To introduce the M5, we must first go back to 1979. The forerunner of M5 was the 1979 M535i. It was based on the first generation 5-series (E12) saloon and modified by the Motorsport department of BMW. By transplanting the 3453cc inline-6 from 635CSi, BMW created a saloon capable of 218 horsepower, 130 mph and 0-60 mph in 7.3 seconds. That kind of performance was previously unheard for a medium-size saloon. In 3 years, a total of 1410 units were sold. M535i E28 (1984-87)
 When the E12 was upgraded to E28 5-series, the M535i was also renewed. Massive aerodynamic kits and upgraded suspensions improved its appearance and dynamics, but the 3430cc engine kept horsepower unchanged. Still, at the time Autocar magazine praised its good road manner - fine handling, supple ride, accurate steering and of course, that smooth and flexible straight-6 that characterized all contemporary BMWs. Sales surged to 9483 units because the car was built in the regular production line instead of the inefficient Motorsport department. M5 E28 (1985-87) M5 with optional aero kits from M535i While M535i enjoyed great sales success, the Motorsport department was working on an even hotter car. Strangely, it did not have the aggressive aerodynamic kits like M535i, but under the sheep skin was the same engine as M635CSi - yes, that 286 horsepower 24-valve 3.5-litre straight six which was derived from the mighty M1 supercar ! call it "wolf in a sheep's skin", it could top over 150 mph and storm from rest to 60 mph in about 6 seconds. Yes, actually a bit faster than M635CSi because it was around 50 kg lighter.  As the
name "M535i" was
already occupied, BMW simply called it M5. This explain why M635CSi and
M5 had
different name format despite of using the same engine.When Auto Motor und Sport magazine tested the car in 1985, it found the M5 not only very fast, but also very well mannered - superb road holding, safe handling, good high-speed stability, comfortable ride, flexible and torquey engine, linear power delivery, slick and precise gearshift, light and accurate steering… the only complaint was the excessive wind noise caused by its ancient shape with 0.37 drag coefficient. With only 2180 cars built in 3 years, the first generation M5 could not be described as popular. This was partly due to the high price, partly due to the existence of M535i and M635CSi. Admittedly, its dull look was also a resistance to its sales, especially compared with the handsome M635CSi. M5 E34 (1988-95) While E28 5-series was an outdated design (its roots could be traced back to E12 in 1972), the all-new E34 5-series was thoroughly modern, handsome and advanced. Its chassis was massively better - much stiffer, better isolated and aerodynamic efficient. It got much more matured and refined.  The new
M5 was also greatly
benefited by the progress of E34. Inevitably, the car got heavier, so
the
Motorsport hand-built straight-6 received a capacity increase to
3535cc. Now
the new engine pumped out 315 horsepower and 266 lbft of torque.Nevertheless, the extra horsepower was not enough to compensate the 200 kilograms it gained. Magazines found the second generation M5 was actually a little slower than the original, although it took a big leap in ride and handling. More worrying was the emergence of stiff competitions. In 1989, Lotus converted Opel Omega into a fearsome performance saloon - 377 horsepower, 5.1 seconds from 0-60 and 180 mph top speed. Munich was shocked. Next year, it got another attack from its backyard - Porsche helped Mercedes to produce a V8-powered 500E. Both cars represented serious threat to the M5.  In 1992, BMW Motorsport
finally
responded by enlarging the engine - both bored out and stroked out - to
3795
cc. This was the largest and also the last evolution of the M1 engine.
It
pumped out 340 horsepower at 6900 rpm and 295 lbft of torque at 4750
rpm. Now
the car could easily reach the regulated top speed of 155 mph. 0-60 mph
was
reduced to 5.6 seconds. On the other hand, handling was improved by the
adaptive damping and the optional "Nurburgring" sport suspension
package.Two years later, the M5 received its first 6-speed gearbox along with stronger brakes and 18-inch wheels. As Autocar found, 0-60 mph reduced further to 5.4 seconds, 0-100 in 13.6 sec and, interestingly, 170 mph top speed. Seems that BMW forgot to install speed regulator to the test car. The M5 might not match Lotus Omega for speed, but its handling and overall fineness was beyond approach. Therefore it regularly topped the performance saloon ranking in magazines' contests. The E34 M5 was more matured, refined and luxurious than the original yet provided Ferrari-matching performance and handling. This proved to be a winning formula. In 7 years, it received 12,100 orders. Now BMW was getting more and more ambitious… M5 E39 (1998-2003)  Like the leap taken from E28 to E34, the E39 body was another major advancement over its predecessor. It got bigger, roomier and more aerodynamic efficient. The cabin was stylish, high quality and ergonomically sounded. It employed aluminum Z-axle suspensions instead of the old semi-trailing arm. All suspensions were mounted on NVH-absorbing sub-frames. This mean it rode and handled even better than before. Because of the sales success of E34 M5, BMW projected to build even more E39 M5. To do that, the new M5 would be assembled in the regular production line instead of M GmbH, although the engine would continued to be hand-built by the latter.  After
serving M cars for 20 years,
the legendary inline-6 finally retired. Taking its place was a new
4941cc
32-valve V8 derived from the company's mass production 4-ltire V8. It
got
Double Vanos (variable valve timing at both intake and exhaust valves)
and
electronic throttle. Max power raised to 400 hp at 6600 rpm. At the
time being,
this was the most powerful production saloon in the world. It could
take the
heavyweight (1720 kg) M5 from 0 to 60 mph in 5 seconds flat. If
deactivated
speed regulation, it could top more than 180 mph.The big V8 changed the character of M5 somewhat. Although it would spin happily towards 7000 rpm, it no longer needed to be revved hard, because there was tremendous bottom end torque and as much as 369 lbft available at only 3800 rpm. This mean the car was more relaxing to drive. However, if the driver really want more thrill, he could press the "Sport" button on the dashboard. This would sharpen the response of the drive-by-wire throttle instantly and weigh up the steering. Unlike some rivals at the time, the E39 M5 employed conventional suspensions without any electronic damping. However, its tuning made the right balance between sport and comfort, delivering great body control and livable ride. The car was agile and well balanced, so it felt completely at home on narrow B-roads, which was unusual for a big and powerful performance saloon.  However,
perhaps most brilliant was
its ability to power slide. It took some speed and provocation to do
so, but
once its tail was sliding, the action was progressive and the driver
could
easily hold the slide by cooperating throttle and steering. This was a
unique
feature not found in other contemporary performance saloons. It made
the M5
very entertaining to drive.Since the arrival of Audi RS6 and Mercedes E55 AMG in 2002, BMW M5 was no longer the most powerful nor the fastest sports saloon in the market. Nevertheless, in terms of driving thrill and overall satisfaction, it remained unbeatable during its whole life. 20,500 cars sold in 6 years proved its leading status in the luxurious sport saloon market. |