BY TIM BRITTEN | 13th Apr 2004
In what seemed a less than successful transmutation from sedan car into open-top convertible, the previous A4 Cabriolet was not a great upholder of the Audi tradition.
It suffered the woes that can afflict four-seat convertibles if the designers don’t get it right: Even the test cars – which are usually prepared in a way that shows the model in its best light – suffered creaks and groans as well as the hard-to-avoid scuttle shake around the dashboard area.
In fact, on one example we drove, the driver’s door had also dropped out of alignment, no doubt due to the stresses imposed by the lack of the sedan model’s body-stiffening metal roof.
The Audi was not alone, of course. It’s not easy to develop an entirely rigid four-seat convertible and even the likes of Mercedes and BMW are not able to achieve sedan-car standards of torsional or bending strength.
Saab’s previous 9-3 was no shining example either, even though it was better than the original, 1980s convertible.
But let’s forget all that. Audi now has an all-new A4 Cabriolet and, like the latest Saab 9-3 convertible, it’s a dramatic improvement over its predecessor.
In fact it’s more than that, because it now joins the front-runners in its segment.
The Audi immediately feels taut and strong, very much in tune with the A4 sedan’s classy, quality image.
The feelings of structural integrity are no surprise when you consider the new Cabriolet is twice as stiff as the previous model. This was achieved partly because the open-top version was factored into the new A4 range right from the beginning.
Audi says much of the new-found strength was achieved through the use of high and ultra high-strength steel panels on more than half the body shell’s weight, plus a rigid, bolt-on front subframe and additional, diagonal struts at both front and rear. Further strength also came from better production-line welding techniques.
The A4 Cabriolet is also bigger than before, and feels it. This is aided by a 100mm wheelbase stretch that noticeably opens up the rear seat area and delivers shoulder width increases of 33mm in the front and 52mm in the rear.
The boot is bigger too big enough that Audi is able to claim the A4 Cabriolet has the ability to carry two golf bags with the roof up – although the space decreases significantly when the roof is lowered into its special, flexible cradle.
The Cabriolet looks pretty good too, a successful translation of A4 styling themes that is particularly enhanced by the fact it sits 20mm lower than the sedans. A nice Audi touch is the finishing of the front windscreen pillars (specially reinforced in the Cabriolet) in brushed aluminium.
And the standard, smallish, 16-inch alloy wheels actually fit nicely into the low-slung side profile.
The convertible top (with glass rear window) is cleanly shaped and smooth in operation too, electro-hydraulically folding itself out of the way in not much more than 20 seconds – which is quite fast for a big, four-passenger roof.
From a safety perspective the Cabriolet measures up pretty well. Audi says the overall passive (post-collision) safety compares favourably with the A4 sedan.
Two automatic, pop-up rollbars, emerging from behind the rear seats and working in conjunction with the reinforced windscreen pillars, protect the passenger area in the event of a rollover.
And there is of course the usual complement of airbags, including seat-mounted side bags in the front to protect from side-on collisions.
Two powerplants are available with the Cabriolet a recently introduced 1.8-litre turbo and Audi’s 3.0-litre V6. Both come only with Audi’s Multitronic constantly variable transmission.
The test car was the new four-cylinder turbo, which is the "entry level" version at around $85,000 - or about $20,000 less than the V6. That makes it dearer than the base Saab, but a lot less than the BMW 330i convertible (which is about lineball with the A4 V6).
Equipment levels are (just) up to scratch for the money: leather upholstered seats with electric lumbar support in the front, trip computer, rear-seat ski-bag, CD player, climate-control air-conditioning, alloy wheels and remote central locking are standard.
The 1.8-litre turbo/Multitronic transmission pairing makes a good combination. The 20-valve, 120kW engine is deceptively smooth and the Multitronic squeezes every ounce of potential out of it.
Because the Audi constantly variable transmission (CVT) system uses a multi-plate clutch for initial takeoff (others use a fluid-coupled torque converter system), there’s a slight stuttering from the transmission as the car moves off but, once under way, Multitronic still rates as possibly the best auto transmission in the world.
Acceleration is a seamless process. Depending on what the driver requests, the engine will quickly find the right spot in the powerband, then hold it until the desired road speed is reached. Flatten the accelerator, and the tachometer will wind up to maximum power rpm and maintain it until the driver backs off.
The results are amazing. No pausing as gearshifts take place – just a steady, constant surge of power. For descending, Audi has invented a set of six discrete ratios on the constantly variable pulleys that allow Multitronic to be used for engine braking, just like a conventional auto.
With this efficient and effective use of engine power, the A4 Cabriolet combines its lower-set suspension and sharp steering to behave much more like a sporting car than the previous model – even though the alloy, all-independent suspension actually proves to be quite absorbent when it comes to dealing with patchy road surfaces.
The A4 is impressive when it comes to aerodynamics too. The roof-up aerodynamic Cd figure is an impressive 0.30 and drops to just 0.33 with the roof down, which is exceptional for a convertible.
Combined with the fully-lined roof, this makes the A4 Cabriolet almost sedan-like, in terms of noise levels, when it comes to cruising the highway with the roof up.
Naturally, it comes with the normal array of electronic dynamic aids including Audi’s electronic stability programme (ESP), four-channel anti-lock braking with brake assist and electronic brakeforce distribution.
Overall, the impression is of a very refined, very durable, quality convertible. The A4 Cabriolet is a class act, a worthy bearer of the Audi symbol and a serious challenger in the luxury four-seat convertible market.