BMW 3 Series Convertible 2007 Review

BMW E93 3 Series Convertible

Not so much
>> No spare wheel
>> Usual CC-style luggage compromise
>> Spoils you for fixed roofs and soft-tops

It's one of the great propellants of our time. It follows that you'll also be aware this powerhouse is available in the 3 Series sedan and coupe.

Well, as a finishing touch, the 335i now comes with air. As does its 325i sibling. That's not just automatic dual-dial air-conditioning, but also the real stuff, which fondly ruffles your tresses or massages your pate while offering the sky for a ceiling and exposing your full senses to the prevailing sights, sounds and smells.

Yes, the 3 Series Convertible is back. And better. Unlike the earlier Convertible generations (launched in 1986, 1993 and 2000 respectively), this fourth open iteration (coded E93) breaks with BMW soft-top tradition to join the coupe-convertible brigade with a folding hardtop.

And a particularly neat one at that.

Needless to say, the $26,600 price difference between the 325i and 335i covers much more than the respective engines. For example, the 335i has bigger brakes than the 325i, and where the smaller model has 6.5-inch colour monitor and Business grade sat-nav system, the more upmarket edition has an 8.8-inch display for its Pro grade navigation system which is accompanied by voice recognition and TV receiver.

Both models' standard fare includes push-button engine start/stop, bi-Xenon headlights with washers, remote central locking, front fog lights, automatic wipers, automatic headlight control, dual zone climate control, multi-function steering wheel, CD six-stack, trip computer, infrared-reflective leather trim (to minimise the sun's affects), auto dimming interior mirror, front seat heating, retractable centre front armrest, leather, and four no-cost alternatives to the standard gloss black interior hard trim.

Being BMWs, both offer more than a few options, some of which allow the 325i's equipment status to match the 335i's. Thus, for $3300 extra the 325i can have the Pro navigation/TV/voice system. Similarly, where the 325i has 17-inch alloys with 225/45 size tyres as standard, an extra $2100 buys the 335i's package with 18-inch wheels and 225/40 front, 255/35 rear tyres.

Other 335i features to which the 325i can upgrade include $860 adaptive headlights, $350 front parking sensors, $1250 sports front seats and front seats' electric lumbar adjustment at $600.

However, the 335i automatic's $200 paddle-shift option does not extend to the 325i auto.

Among other things, both versions offer $1600 metallic paint, $1800 active cruise control (replacing standard cruise control), $2700 active steering system, $800 sports suspension and Comfort Access luggage loading for $1250.

MECHANICAL   
The Convertible's platform is derived from the Coupe's, strategically reinforced to ensure that it is the stiffest, strongest and safest Convertible body-chassis unit BMW has built. In fact the new coupe-cabrio claims to be a whopping 50 per cent stiffer in the body than the previous model, which wasn't noticeably limp-wristed.

All-up, the new Convertibles weigh about 1665kg and 1735kg respectively, or about 200kg more than the Coupes. Since that's about the same difference as in the previous pairs of open 3s, the latest structure is a significant advance in weight-versus-rigidity terms.

Around 80 per cent (160kg) of the weight increase is owed to the chassis reinforcements, with the roof accounting for the other 40kg.

Although BMW doesn't say the folding roof design is all its own work, it doesn't credit any of the independent folding roof specialists with input, either. Regardless, it is a very neat three-piece design using a minimum of operational hardware. A single electric motor drives a husky oil pump that powers four pairs of hydraulic rams which are organised to lower and stow the roof in just 22sec, and to raise it in a second or so more.

The operations' seamless alacrity puts the BMW among the front runners in the current crop of CC models for retraction and erection alike.

Incidentally, but not unimportantly, given some consumers' disquiet about the reliability and longevity of foldaway hardtops, BMW says its roof performed 15,000 open/close cycles during the development phase. Which indicates durability isn't an issue, even if you maybe intend willing the car to a yet-unborn grandchild.

On other mechanical fronts, the 325i and 335i Convertibles are essentially interchangeable with their coupe and sedan stablemates. Thus the 325i's 2.5-litre engine features Double Vanos variable cam phasing and Valvetronic valve control, providing it with 160kW maximum power at 6500rpm, and 250Nm maximum torque spread from 2750 to 4000 rpm.

The 3.0-litre 335i combines two turbochargers, direct-injection and Double Vanos to realise exceptional driveability and performance, culminating in 225kW at 5800rpm and a massive 400Nm maximum torque delivered from just 1300rpm through to 5000rpm.

The multi-link rear suspension and strut front suspension with double-joint lower control arms are familiar from the related 3 Series models, but the springs and dampers are tuned specifically to the Convertible.

Whereas the 335i Coupe and sedan have had sports suspension as standard, the Convertible introduces a 'cruising' suspension with each engine, and an optional firmer, lower 'sports' set-up at extra cost. This arrangement now applies to the other models also.

PACKAGING   
The previous soft-top Convertible's cabin space was pretty good, but the E93's gains increased rear shoulder and elbow width. That said, like the 3 Series coupe, the convertible is strictly a four-seater.

As ever with cars of the CC kind, rear leg space is far from galactic and occupants of even average adult height must negotiate their knee room; usually easier arranged behind the front passenger than the driver.

Like many of its ilk, the BMW includes a lidded ski port between the rear seat and luggage boot. But unlike most, the BMW's port is large enough for a golf bag. It can be accessed when the backrest is upright, or is lowered to cover the cushion, releasing extra luggage space when the car is used as a two-seater. A tailor-made bag is available for the purpose.

From the outset of the Convertible's design, BMW insisted that the new model's rear deck be as stylishly flat as those of its soft-top predecessors, and the result is undeniably more graceful than other CCs' humped decklines. However, the modest boot capacities of 350 litres (roof up) and 210 litres (roof down) are only average at best, and come, remember, without a spare wheel. However the boot usefully includes a luggage net, elastic tie-down strap and fold-out bag retainers.

To save completely raising the roof every time luggage is loaded or removed, the optional Comfort Access system quickly lifts the roof about halfway for ample access.

Preventative measures include arresting brakes with ABS, brake assist and brake pad wear monitor, tyre pressure monitor, cornering brake control,
traction control and dynamic stability control. That's in addition to inherently responsive handling and other first class chassis attributes.

In the passive column, the Convertible has two front airbags, plus two front seat sidebags offering protection to head as well as body. Integrated with the seats, the front belts incorporate pre-tensioning and load limitation. The rear seats have conventional lap-sash restraints.

Behind the BMW's rear headrests, pop-up roll-over bars extend upwards in event of a triggering impact, to increase the protection afforded by the reinforced A pillars and windscreen frame.

COMPETITORS   
As a coupe-cabrio, the 3 Series Convertible has no direct rivals.

The closest (indeed, only) neighbouring foldaway hardtop is the handsome and plush Volvo C70 which (overlooking the $69,950 entry level LE model) gives its best shot as the $79,950 T5 turbo model. Offering rousing performance, the C70 T5 goes hard and cruises well enough, but the grasp of its driving dynamics are ultimately decided by limitations of the front-drive chassis.

Beyond the Volvo C70, no other coupe-cabrio comes within coo-ee of the BMW Convertible. Others in that part of the market are soft-top convertibles, among which only the Mercedes CLK has rear drive. Excluding two humungous V8s, the three most cogent variants of the CLK Cabriolet are priced from $99,400 (1.8-litre supercharged four-cylinder) through $109,100 (3.0-litre V6), to $134,100 (3.5-litre V6).

Audi and Saab also field established rag-top models within the price sectors where the E93 Convertibles have re-written the rules of engagement.

ON THE ROAD     
With the outstanding twin-turbo 335i getting the bulk of rave notices whenever the sensational performance blows another mind, it's easy but mistaken to regard the 325i as the poor relation. In fact, for everyone not obsessed with the quickest /costliest solutions, the 325i is a honey in its own right.

With 160kW and 250Nm available, the naturally aspirated 2.5-litre engine provides ample performance (for example, 0-100km/h in 7.8 or 8.4sec for manual and auto respectively), with deliciously smooth and creamy delivery throughout the rev range.

While the junior six pulls elastically from low speeds, it feels and sounds to enjoy nothing better than a good spin through the upper rev band.

The 325i also drives with enthusiasm, brakes powerfully, handles superbly and rides with measurably absorbent comfort while dispatching rough roads with almost total lack of body flex. Only very occasionally do big, sharp bumps elicit an incriminating shudder from the side windows.

There may also be comfort in knowing that besides saving on initial outlay, the 325i promises economical fuel consumption. It accepts 91RON, or higher, and yields combined-consumption of  8.9 and 9.2lt/100km for manual and auto respectively.

Of course, economy isn't necessarily a high priority with the 335i which asks for either 95 or 98RON fuel and quotes 9.9lt/100km with either transmission.

Given its head from standstill the superlative six rockets to 100km/h in just six seconds as an automatic, or two-tenths less as a manual. BMW expects over 90 per cent of Convertibles to be automatics, and you don't have to drive it far or fast to understand the rationale. The 335i brings out the best in the auto which, in both models, shifts through the gears more quickly and smoothly than the manual, and gives superior rolling response for overtaking.

It's when the Convertible is given a serious squirt that the 335i's edge becomes graphically self-evident, not only in the mighty shove it unleashes but equally in the aural effects. Where the 325i sounds great under ropey acceleration, the 335i's urgent wail is spine-shiveringly glorious.

Performance apart, the most noticeable differences between the two models are steering feel, ride and handling. And that's interesting because the only physical difference is in the respective 17 and 18-inch wheels, and lower profile tyres.

Even so, it's clear that the 335i steers into corners just a touch more promptly, handles just a bit more responsively, and rides discernibly more firmly… Which doesn't always mean better, than its deliberately less racey sibling.

Either way, BMW has again upped the ante because, for those who appreciate openness and have budgets to suit, the 325i and 335i Convertibles are in many ways the top of the tops.

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