To
car enthusiasts all over the world, the launch of a new BMW compact
saloon
is always a big news. Since the 02 series invented this category of
cars
in 1967, every BMW compact saloons were highly praised about their
dynamics,
no matter engine or handling. The first 3 series succeeded to bring
higher
performance by its 6 cylinder engine. The second generation diverted to
more choices including 4 doors, convertible and touring. The third
generation,
also the most successful one, raised dynamics to even higher level
while
provides quality matching Mercedes-Benz. After 8 years, everyone is
waiting
for the fourth generation with high expectation. As usual, the new 3 series grows in every dimensions - 25mm in wheelbase and 38mm in width free up the originally cramped cabin. Now 6 feet passengers can rest comfortably in the rear seats, with sufficient of knee room as well as shoulder room. It is still not class-leading when compare with Peugeot 406 and Volkswagen Passat, but easily beat its most likely rivals - Alfa Romeo 156 and Audi A4. This could be a crucial advantage. Another improvement is the refinement. Since its predecessor was virtually unbeatable in dynamics (some may say Alfa 156 overtook it in the last minute, but I don't agree.), BMW made most effort in upgrading refinement and quality. Open the door, you will find a very classy interior just like a downsize 5 series. Turn on the engine and you will discover that its engines become a lot more flexible that you need not to work too hard to access the same performance. Its ride is the most improved aspect. While preserving high level of stability, the suspensions (still MacPherson and Z-axle, but with different spring / damping rate and aluminium arms) become as supple as the 5 series. You wouldn't believe a car in this class and this size could ride so comfortable. Although the previous 3 was virtually perfect in engine and handling, the new 3 still improves a little, if not huge. The grass-root engine is basically the previous 1.9 litres sohc unit with variable intake manifold, but now added with twin balancer shafts to reduce NVH. It becomes as smooth as a six cylinder. Those real 6 pots engines also received improvement - Double Vanos variable valve timing now extends service to the exhaust valves, thus leads to a broad torque curve and brings the peak torque earlier, from 3950 rpm to 3500 rpm. "Smooth, responsive" and "the best six cylinder in the world" were what I described the previous engine. The new engines are even better. Handling enhancement might be less noticeable. Due to improved sound insulation and supple ride, you may subjectively feel less exciting than before. In fact, the new 3 corners more stable, with less body roll due to the stronger chassis and wider track, which grew 63 and 57mm in front and rear respectively. Anyway, its cornering ability remains unmatchable. On demand, power slide is still accessible in this rear-driven saloon, although normally it is extremely secure. Steering remains very communicative. As a whole, the
new BMW 3
series becomes far more refined and comfortable than ever, but remains
as exciting as before. It might not be as driver-biased as before, but
still manage to cope with Alfa 156. In my opinion, the Alfa can steal
some
sales by its 2.0 twin spark version, since it is cheaper and faster
than
318i. However, Alfa V6 can hardly compete with 328i. Without
compromising
with cost problem, the 328i has the best engine and the necessary power
to make itself a perfect car. |
The above report was last updated in 1998. All Rights Reserved. |
330xi Touring4-wheel-drive sedans are not very popular in Europe, but American buys a lot of Audi and Subaru equipped with full-time 4WD. That calls for BMW’s re-enter the 4WD sedan market with the 330xi. Yes, it’s "xi" instead of "ix", the latter appeared since the E30 325ix but disappeared in recent years. However, the new 4WD system is derived from the X5 SUV rather than the previous ix.As you might know, the X5’s system is a very simple permanent 4WD, with 3 regular differentials but no Limited Slip Differentials or differential lock-up at all. That means in the absence of tire slip, torque split between front and rear wheels is always 38:62, preserving most of the rear-bias character of the BMW. A little bit knowledge with 4WD will tell you this setup alone can’t deal with poor conditions, say, when one wheel rides on mud and loses traction, the basic principle of differential will transfer even more power to that spinning wheel and ignore other wheels that have traction. Therefore BMW employs electronic brake differential to get out of trouble. What is that ? as you might already learned that in my Technical School’s article about Porsche EBD, it is not actually a real differential. EBD employs ABS hardware to detect wheel spin, then apply braking to the spinning wheel so that the differential will transfer more power to other wheels. The same goes for the torque split between front and rear - apply brake force to rear wheels will lead to the transfer of more torque to front wheels by the center differential. Using EBD instead of LSD saves a lot of money. Then why not Audi or Subaru employ that ? because EBD is far less effective. While LSD can implement torque split continuously and fluently, EBD applies brake in discrete and jerky style, because until today we still fail to make a braking system operate smoothly (ABS just lock and loose at a very high frequency). Moreover, the response is relatively slow. Therefore whenever 330xi rides on muddy surfaces, it can’t overcome that as smooth as A4 Quattro. It struggles in the mud, switches on the off individual brakes times to times, moving slowly, worrying the driver. If the surface is really bad, brake discs may get overheated before overcoming the trouble, then the electronic throttle will automatically reduce engine output. Driving quick on wet and muddy roads, the rear-bias manner fail to provide the security of Quattro and leads to going side way if too fast. Obviously, 330xi
isn’t the
best all-weather 4WD sedan. Care must be taken on the worst road and
weather.
However, on dry gravel it goes very well yet provide superb ride
comfort
and noise insulation. Moreover, with the new 3.0 litre engine good for
231 hp, the 330xi Touring matches the performance of the previous 328i
sedan. |
The above report was last updated on 9 July 2000. All Rights Reserved. |
2002 update and new 318iLate 2001 saw the whole 3-series sedans receiving a sportier setup mirroring the Compact in an attempt to restore keen drivers' faith. Springs and dampers of suspensions are firmed up, so is bushings. The new relationship between springs and dampers are quite clever, promising sharper chassis response but almost without any deterioration in ride quality - at least on German roads. Brilliant !The steering rack is also tightened - now it takes 3.0 instead of 3.2 turns from lock to lock - while reduced power assistance increase steering weighting significantly. Now the steering feels more communicative. In combine with the aforementioned suspension upgrade, the new 3-series turn in sharper, balance better in corner, especially at the limit. Biggest news is the adoption of a new 2.0-litre four-cylinder engine for 318i. As the old one actually displaced 1.9 litre, you won't be surprised that the new engine displacement does not match with model number. Compare with the old 8-valver, the new engine is far more advanced. Built in BMW's engine plant in UK, it is constructed entirely in aluminium, having 16 valves, Bi-Vanos, 2-stage intake manifold and the famous Valvetronic fuel-saving technology (first appeared in 316ti Compact). According to EU's test data, it drinks 23% less petrol than direct-rival Mercedes C180. The new engine is perfectly smooth across a wide range of rev. Simultaneously, throttle response is crisp (should we call "throttle response" ? Valvetronic has no throttle) and the engine generates noises like any typical BMW straight-six. Both 143 hp and 147 lbft are competitive, especially the latter. However, biggest surprise is the introduction of SSG (Sequential Shift Gearbox) to 325 and 330i. BMW claimed it is a simplified version of the M3’s sequential manual box, but it is actually built around the regular 5-speed manual rather than the M3's 6-speeder and most importantly, the shift mechanism is supplied by Italy's Magneti-Marelli instead of Siemens. You might remember Magneti-Marelli is the maker of Alfa Romeo's Selespeed and Ferrari's F1 system, so SSG should be much cheaper than the SMG. Unfortunately, shift response is far slower than SMG. There are 3 modes: in "Normal" mode, shift takes 400-500ms; in "Sport" mode, it is reduced to 250-300ms but shift quality is less smooth; in "Launch" mode, 150ms can be achieved from first to second gear. Lastly, the
late-2001 update
completes with a slight facelift. This include restyling to headlamps,
grille, front and rear bumpers. Prettier they might not be, but they
remind
you this is a better-than-ever 3-series. |
The above report was last updated on 17 Sep 2001. All Rights Reserved |
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