The A5 Sportback receives the more powerful engines from the A4 range and as a result, even the slowest model gets to 62mph in a brisk 8.0 seconds. Go for an automatic model and this drops to 7.9 seconds, while the all-wheel drive version cuts that to 7.4 seconds, with barely any wheelspin as power goes to all four tyres.
The 3.0-litre diesel shaves off a further second, with the 252hp 2.0-litre petrol taking just 6.0 seconds. The performance-oriented S5, meanwhile, requires a mere 4.7 seconds. All models are capable of at least 145mph, bar the most frugal “Ultra” diesel models, which run out of steam at 130mph.
As all engines are available with Quattro all-wheel drive – the more powerful models including it as standard – the Sportback has no problem transmitting its power to the road. At launch, only the 190hp 2.0-litre diesel – in front-wheel drive form – is available with a manual gearbox, while all other models include a seven-speed dual-clutch automatic. The S5, though, features an eight-speed standard automatic gearbox.
The S Tronic gearboxes are super-slick and quick to change gear, making the only downside the more-than-£1,500 premium. For a car of this size that is likely to see its fair share of long journeys, this gearbox suits the car very well – both with the 2.0-litre petrol and diesel engines.
Despite being the initial range-topper, the S5 gets a less sophisticated standard automatic gearbox. In comparison this is slow to change gear and much less suitable for fast driving, pausing notably between you pressing the throttle and it changing gear – making for a frustrating driving experience.
Audi RS 5 Sportback performance
Announced at the 2018 New York Motor Show, the RS 5 Sportback features the very same mechanical parts as the RS 5 Coupe. It'll cover 0-60mph in 3.9 seconds and go on to a top speed of 174mph.
We'll update this review once we've driven it later in 2018.
Whether you go for a two- or four-wheel drive version, the A5 Sportback feels safe and secure on the road. The steering is direct and provides a reasonable feeling of control, proving light enough for easy manoeuvring, while weighing up nicely at speed.
Go for a front-wheel drive diesel and the Sportback has precise steering and offers plenty of grip in the bends, though the all-wheel drive petrol we drove felt like it rolled more in the corners, offering less confidence in the level of grip available.
We also tried a 2.0-litre diesel with Quattro and the £600 optional Damper Control suspension. This model felt very planted around bends, absorbing bumps without being thrown off course despite the large 19-inch alloy wheels fitted to our test car.
The S5 Sportback proves sharper still, with total traction from the all-wheel drive system and very sensitive steering at lower speeds in our test car, which was fitted with the £950 Dynamic Steering option and Damper Control – in this case £900. Use the full power of the engine, however, and the car feels soft, with the suspension allowing a little too much roll in turns to satisfy faster drivers.
Our test car also had the £1,200 sport differential, and with this fitted the S5 can be made to slide around corners when pushed hard, although it provides a much greater safety net than a similarly powerful two-wheel drive car where all the power goes to the rear tyres.