BMW 325i, 2 and 4 wheel drive
The new top model in the small range from BMW, the 325i, follows the Munich company’s established approach to new product development — steady and sure, rather than radical. No car manufacturer nowadays can afford to announce a new model which is inferior in any measurable respect to its predecessor, no matter what striking advances it may display in other areas. Nevertheless, perhaps because of the technical slant of their presentation, it is the German firms who seem to specialise in boasting percentage gains in all quantifiable factors.
Thus the 325i can claim that the 8% enlargement to 2.5-litres from 2.3 is accompanied by 10% better torque, 15% more power – and 3% better specific energy. The news that this makes the 171 bhp 325i the most efficient two-valve engine for its size available in Germany may not translate into showroom excitement for the customer, but it does indicate the emphasis on continuing invisible improvements in the century-old petrol engine.
What will sell the car, though, is performance. Acceleration to 62 mph drops from 9.0 to 8.3 seconds, and a top speed of 135 mph is achieved burning less fuel than ever. This is apparent in the impressive flexibility of the new power unit (specially developed for this car, not borrowed from the existing 525i) whose higher torque occurs at the same 4,000 rpm. Otherwise, the driver might be in a 323i; pleasant steering, crisp ride, that unimpeachable instrumentation. To improve weight distribution and traction, the battery has been moved to the boot, and the only visible sign of all this is the single digit which alters on the boot badge. Prices are £11,495 for two doors, £11,920 for four.
At the same time as a short drive in the 325i, I was able to try a much more significant car — also called the 325i. This is the long-awaited four-wheel-drive version which combines the 2.5-litre motor with permanent drive to all wheels, split 37%:63% front to rear. Viscous locks in centre and rear diffs give variable and entirely automatic traction control much as in Ford’s XR 4×4, but the most interesting element is the anti-lock braking system which comes as standard. Because the wheels in a wholly or partially locked 4WD system can no longer rotate fully independently of each other, previous ABS systems could be fooled into allowing all four wheels to lock by assuming that the car had actually come to a standstill, there being no external reference to tell whether the vehicle was moving or not. This is why Audi Quattro diff-locks automatically cancel the ABS. However, BMW have added just such a reference in the form of an accelerometer between the front seats, thus making possible full-time ABS under all conditions.
Although this new generation of 4WD cars is aimed at increased road performance (and therefore safety) rather than cross-country stuff, BMW have increased the ground clearance by 1.2 in, which must help in snow, and it was in fact on a glacier that the company chose to present the car to European journalists. It was a curious sensation, accelerating confidently uphill and recklessly standing on the brakes in a corner, feeling the car respond obediently as if on concrete while ice and slush fountained up all around from the standard road tyres. The braking system is tuned so that the car tends to turn in the same curve as the angle of the front wheels — or in other words, it does exactly what a driver without the benefit of skid-training might expect it to. There is no sensation through the steering wheel of the power going to the front wheels, and very little of the thumping apparent through the brake pedal on some other systems when the ABS is venting pressure, although the driver can tell that the system is in action, which gives valuable information on road conditions.
With flared wheel arches and narrow sill extensions, this is the one small BMW which is distinguished from its brethren, and some may not feel that the visual differences are enough compared to the extra cost, still to be fixed. Yet the BMW marketing policy has successfully exploited very fine model gradations, as has Ford’s, and there is no reason to suppose, given the dynamic excellence of the 4WD car, that this will put customers off a conventionally styled but convincingly capable car. — GC.