Rigid air



At last, BMW has got around to replacing its old (launched in 1986) range of 3-series convertibles with the current shape, although the four-cylinder 3I8i convertible remains available in the old format for £19,245. The new 325i is expected to command £28,000, complete with many features that are offered only as options in Germany.

A further £2000 will be required if you fancy the lightweight (just 64 lb) aluminium hardtop with its noticeably large rear screen, which totally alters the profile. It allows BMW yet another weapon in the niche marketing Blitzkrieg it is waging as Mercedes whips up pre-launch enthusiasm for the forthcoming C-class, which replaces the 190 in June (in lhd markets).

BMW uses the two-door coupé body as basis for the convertible, reinforcing the front screen pillars as fixed roll-over protection and providing ample extra strengthening elsewhere to compensate for the inevitable reduction in torsional stiffness. Automatic pop-up aluminium arms, standard in the UK, are also fitted to provide further protection in the event of a mishap. The result is an integrated convertible of rare rigidity; the penalty is a substantial increase in kerb weight. The two-door saloon is some 264 lb lighter. Performance claims are slowed accordingly, but drifting along at between 70-90 mph in southern France you care little about the extra second or so it takes to reach 60 mph from rest (BMW claims that it will attain 62 mph, from standstill, in 8.6s).

The test drive started well. Lowering the hood, via one handle and an electric button, is toddler’s play, and those six cylinders sound better than ever as you ascend the foothills to the north of Nice. As the corners get tighter, you appreciate the extensive grip of standard 205 rubber; the cabrio actually feels a little tauter than the original E36 saloons and coupés. Springs, dampers and roll-bars have all been “retuned”, in BMW’s non-specific words, and the result works well under duress.

We were not so enchanted with the ASC traction control that not only reduces power sharply at the merest whiff of oversteer, but also taps back remorselessly against the throttle, long before the limits of adhesion are broached. Happily, it has an ‘off’ switch.

Sometimes, the stiffer suspension rates work against BMW, pounding the structure with audible blows over bumps, particularly at low speeds. However, the 3-series’ valued ride quality remains.

The hood is fabricated in three layers of polyacrylics with cotton strands, and now has a charcoal lining that hides the patented roller bearing action for the support spars, linkages and rods. The rear window is glass, and can be zipped in and out as required. The whole lot folds away beneath a cover in a manner reminiscent of the £60,000 Mercedes SL; it can even be retracted on the move, so long as you aren’t exceeding 3 mph. During operation, the side-windows lower themselves by half an inch if you happen to have forgotten to perform the task yourself. All sideglass is electrically operated, and there is now a central command button which operates all four panes simultaneously.

Hood up, top speed is 142 mph, rather than the coupé’s 145. More realistically, it is noisy enough to discourage much more than a sustained 100 mph, but cruising at the UK limit is extremely civilised. In practical terms, the soft-top only loses out significantly where rear three-quarter vision is concerned.

Underlining the pace at which manufacturers subtly redevelop even popular products, the 2494cc engine has received a simplified variable camshaft timing system to augment mid-range pulling power, which was notoriously inaccessible on the original dohc 24-valver. The maximum torque figure (177.5 lb ft) has not been revised, but it’s now available 500 rpm earlier, at 4200 revs. The motor is willing to tolerate life without a downchange from 2000-4500 rpm.

Peak power (192 bhp at 5900 rpm) is not affected.

The new 3-series convertible is worthy successor to a model which sold over 140,000 units.

However, rather to our surprise we find that the 3-series which has really commanded our respect of late was not this stylish convertible, but the 324 TD (Turbo Diesel). BMW has long enjoyed continental success with diesel-engined 3- and 5-series models; now, they are coming to the UK.

Recently, I gave an M5 owner a short lift in the TD. He thought I was teasing him when! said it was a diesel. Only a reminder on the fuel gauge convinced him that this 120 mph saloon had sparkless ignition. It’s that smooth. J W