Is the diesel-powered Audi A3 Cabriolet worth considering over its petrol counterparts? Matt Campbell finds out.
Diesel convertibles don’t make a lot of sense to some sports car buyers, but for those who like the combination of low fuel consumption and wind in their hair, vehicles like the recently-released Audi A3 Cabriolet 2.0 TDI Ambition are a perfect blend rather than a compromise.
The German four-seat convertible – which is based upon the A3 sedan this time around, rather than the hatch – is a very different proposition than the cutesy car it replaced. It’s longer and wider, but lighter and more efficient. Add to that you can now buy a diesel version, and it becomes apparent how big a change it has been between generations.
The 2.0 TDI is the mid-point in the A3 Cabriolet range, priced identically to the 1.8-litre TFSI petrol turbo Ambition $51,500 plus on-road costs. That’s $4600 more than the base petrol 1.4 TFSI Attraction and $3000 less than the 1.8-litre quattro petrol Ambition. The A3 Cabriolet line-up was also joined recently by the flagship performance-oriented S3 Cabriolet ($69,200).
It produces 110kW of power and 340Nm of torque, and comes solely available with a six-speed dual-clutch automatic gearbox. Fuel use is claimed at a miserly 4.7 litres per 100 kilometres.
The diesel is a pushy little thing, with a decent amount of shove when you plant your foot at speed. It is, however, slow off the mark both due to some turbo lag and lag that is exacerbated by some low-speed hesitation from the S tronic gearbox, particularly following the engine completing its stop-start fuel-saving trickery at the traffic lights.
There is also the fact that 110kW isn't a whole lot of power to immediately shift a 1480kg vehicle; and nor is it a whole lot for the price. Audi claims an 8.8-second 0-100km/h sprint, which is a full second adrift of the identically priced petrol.
Yet although somewhat grumbly at idle, the diesel quickly smoothens out to become one of the most refined units we've driven, even with the roof down.
Power delivery is impressive in the dry, but as with most front-wheel drive turbo-diesel vehicles with lots of boosty torque, the tyres that also have to handle the steering also scrabble for traction in the wet. The combination of that, and the extra weight of the diesel engine over the nose, means in corners in the wet the Audi will want push on straight rather than bite down on the tarmac.
That understeer isn’t nearly as prevalent through dry corners, where the A3 shares the same lovely balance and sweet damping as the hard-top hatchback and sedan versions. But we can't help but feel the better balance of power and torque in the petrol version (bit more power, little less torque) puts less pressure on its forward wheels, making it easier to drive briskly.
The ride quality of the A3 Cabriolet is largely impressive over the range of roads we tested it on, including highway, city and country roads. However, we did note that the car could dip disconcertingly into larger potholes and ruts – it was never crashy, just a bit jarring – and that it could also pitch from side to side over uneven longitudinal surfaces.
A big question over convertibles is always how much the body flexes and rattles, but during some hard driving over some less-than-stellar surfaces, the A3 Cabriolet felt completely rigid, with little scuttle shake (where the windscreen vibrates and wobbles as the body moves).
Dropping the top is a reasonably quick process – about 18 seconds up or down – which is a fair bit slower than the existing A3 Cabriolet (10sec) but the entire A3 Cabriolet range now has seat heating and neck warmers available on all models ($1250 no matter which specification you choose), which we have plenty of time for.
Thankfully, the boot space isn’t chewed up too much by the roof when you do decide to put it down – Audi claims there is 320 litres of cargo capacity, which dips to 275L with the fabric turret stowed, among the best of any four-seat drop-top.
There is also a 60:40 split-fold rear-seat backrest to dramatically improve load-through practicality, which is extremely rare in the class.
The old car wasn’t the roomiest in the back, and nor is the new model. As with most convertibles, the rear seat is unsuitable for tall adults, with low head and knee room and an upright backrest. It will, however, hold a pair of ISOFIX child seats (or just small children), and ingress and egress is fine, even for clumsy, awkward humans such as your humble tester.
The back seat has small arm rests and a pair of small cup holders as well as a duo of net map pockets, however, which are thoughtful touches often missing from rivals. And completely missing from all similarly-price rivals are rear-seat air vents standard on every A3 Cabriolet; perfect to keep rear riders cool in an Australian summer.
Vision from the driver’s seat is a vital element for drop-tops, too, and there are some issues with the A3 Cabriolet in this regard.
Over-the-shoulder you won’t see a whole lot, and the side and rear-view mirrors are quite small and hard to position, not helped at all by a narrow rear window.
A graceful addition is the standard front and rear parking sensors for all A3 Cabriolets. Option the Technik pack and you also get a semi-automated parallel parking system, a 7.0-inch media screen with reverse-view camera and satellite navigation with MMI touchpad dial system, a colour driver information screen, and an upgraded stereo system. The standard screen size is a 5.8-inch pop-up unit.
The rotary-dial operated MMI system gets easier to understand every time you use it, though its counter-intuitive anticlockwise selection system isn’t ideal. Its Bluetooth phone and audio streaming worked seamlessly during our time in the car, though we wish the Audi had a standard USB input rather than the company’s MDI cable system (which requires you to buy a cable to connect your device).
There’s always going to be a question mark over the notion of a diesel convertible, not just because it seems a strange mix of frugality (we saw about 6.1L/100km over our test run) and fun, but also due to the fact that in slow moving traffic you can hear the engine clattering and feel it fuzzing away under the bonnet.
We’ve driven most of the petrol-powered A3 Cabriolet models, and there’s no doubt they offer a more enticing drive experience. They feel lighter, more nippy and also more refined when the going is slow.
If you want a diesel convertible with four seats in this price range, there’s no other new car option for you to choose. Literally. Impressive as the A3 Cabriolet 2.0 TDI is, though, we’d sooner choose the equivalently-priced 1.8 TFSI.