The 2.2-litre naturally aspirated Astra Convertible has been a huge hit for Holden. Mixing the practicality and style of a fully automatic electro-hydraulic roof mechanism with superb looks and a good equipment level, the $46,000 convertible is currently selling at 238 units a month (all sales data from V-Facts). Last month the nearest competitor was the $36,000-40,000 Peugeot 206 Convertible - with a paltry 64 sales...
In fact, up until now nearly 3500 Astra Convertibles have been sold in Australia - an astonishing number for a car of this type. It's no exaggeration to say that the Astra is the most successful convertible released here in recent times.
And for the competitors, things are about to get worse.
With the advent of the turbo version, the topless Holden has moved its performance aspirations a l-o-n-g way - now it has outright sporting cars in its sights. The power is up by 36 per cent to 147kW, but what's even more important is that the torque delivery of the turbo engine is stunningly strong - 250Nm is available from just 1950 rpm and holds at that level until 5600 rpm. That's kick-arse torque to boot the car down the road whenever you twitch the electronic throttle.
Now it's not only beautiful and practical, but fast as well. How fast? Well, we recorded a 0-100 time of around 7.5 seconds...
And since the price of the turbo car is only 9 per cent higher than you'll pay for the naturally aspirated version, you can see why we think that they'll just walk right out that showroom door. But that's on paper - how does the car work as an entity? The answer is.... very well.
Available only with a manual 5-speed, the Turbo Convertible gains the same upgrades as the Turbo Hatch, released simultaneously. In addition to the engine changes, the Turbo runs firmer sports suspension and 3 and 4mm wider front and rear tracks, respectively. Big (a few years ago they'd have been regarded as huge!) 5-spoke 17 x 7½ alloys are shod with 215/40 ZR tyres; these cover upgraded brakes with 28mm larger front 308mm discs, and 264mm rear discs. Four-channel ABS is standard. The Turbo Convertible also has Electronic Stability Control and traction control.
The stiffer suspension and low profile tyres don't give the harsh ride that the specifications might lead you to expect. In fact, the ride is excellent, even over bad surfaces and potholes. However, body stiffness - as with the naturally aspirated convertible - isn't a strong point of the design. With the top down, the body can be felt twisting (so-called scuttle shake), although is this car we couldn't hear the doors moving around as we could in the last convertible Astra we drove. With the top up, the body integrity is much better.
Handling is excellent - with one caveat. The grip level is high and the chassis progressive and predictable. Charge into a corner too hard and the car is benign and helpful: firstly the traction control (working through the electronic throttle) limits power and then - if there's still too much unwanted behaviour happening - the stability control system will brake individual wheels to keep the car on the driver's steered track. Point-to-point the Turbo can be very fast, even in the hands of a lesser-skilled driver. (The corollary of all that is that when mistakes are made, the car fights every inch of the way to rescue the situation.)
And the caveat? Well, the Astra Convertible Turbo isn't a car to sensorially steer with your finger tips. Despite the ready availability of torque, driving on the throttle isn't encouraged and the communication between the steering and the driver is essentially muted. The vast majority of people will - rightly - regard the handling an excellent, but some drivers will be disappointed that the subtle driving nuances aren't there. More Audi A3 Turbo than Mazda MX5 Turbo, for example.
Even with the stability and traction control systems, this much instantly-available torque being channelled through the front wheels isn't a seamless experience. Torque-steer (where the steering pulls in one direction or the other under heavy low-gear acceleration) can be felt. On some surfaces, it can even be regarded as strong. However, the electronics do keep it largely in check and it's unlikely to get anyone into trouble.
The engine is a bloody beauty. Despite looking a bit aftermarketish in its underbonnet execution (the adaptors on the throttle body and out of the airflow meter could have come from any number of go-fast businesses) the engine drives with supreme OE factory flourish. This is one of the most useable turbo engines available on the market: fantastically quick to boost, an immense band of useable torque, smooth and completely tractable.
Up to 12.3 psi boost is available from the KKK BorgWarner K03 turbo. The turbo is integrated into the exhaust manifold, with this approach reducing weight and size - and presumably, improving turbo response. A relatively small front-mount intercooler is fitted (using data from the OBDII port we recorded intake air temp peaks as high as 60 degrees C on cool 20-degree days) and the engine also uses an oil cooler. Engine management is as you'd expect after experiencing the driveability of the car: cylinder-selective knock control, operation of a variable intake manifold, and electronic turbo boost and bypass valve control. The 2-litre engine uses 'square' 86mm bore and stroke dimensions, runs an 8.8:1 CR and requires premium unleaded fuel. Compared with the naturally aspirated 2.2-litre version, the gearing uses a slightly taller 5th and an 8 per cent taller final drive.
The average fuel economy on test was 10.6 litres/100km.
And what of the rest of the car? It's largely unchanged over the aspirated version, which you can read about at "New Car Test - Holden Astra Convertible". The same excellent roof, leather interior and high equipment level - which includes four airbags, trip computer, heated front seats and climate control. The roof retracts with the greatest of ease (other than pressing a button, the driver doesn't have to do a thing) and the Astra is an easy car to drive, with a progressive clutch and sweet-shifting gearbox.
So what didn't we like? The steering column stalks aren't the best - they tend to wobble around when the end buttons are being pressed - and the roof-up ventilation is poor. Until you get used to it, a tiny delay in the throttle closing when you lift-off is also disconcerting, the rear three-quarter vision with the top up is lousy, and the A-pillars are very thick, restricting vision - especially for small people sitting close to the steering wheel.
But from its fully-galvanised body to its superbly executed roof, from the eminently usable powerhouse under the bonnet to its elegant and practical shape, this is a damn' good car.
Why you would:
- Beautiful and practical
- Excellent roof operation and weather sealing
- Tractable and strong engine
- Only small cost increase over naturally aspirated version
- Extremely safe and predictable handling
Why you wouldn't:
- In on-road tactility not a full-house sporting car
- Body not stiff when roof is retracted
- Torque steer can intrude