Audi provides an enormous amount of choice for people interested in cars based on the A4 platform. The S5 Sportback is one of the many options, intended to appeal to slightly younger buyers than the average Audi customer (average age in the mid to late 40s, probably male and married). It also aims to appeal to those who don't want a saloon or estate but like the idea of decent performance without the running costs of the much faster RS 5.

It's the same shape as the A5 Sportback but has a more powerful engine than anything in that range - a supercharged 3.0-litre six-cylinder unit producing a maximum of 328bhp. This unit is linked with a seven-speed S tronic semi-automatic gearbox and quattro four-wheel drive. There's a standard model and a more expensive one called the Black Edition, which has more equipment.

Performance

The top speed of the S5 Sportback is electronically limited to 155mph, and 0-62mph takes 5.1 seconds, which is certainly brisk but only eight tenths better than the A5 with the more economical 3.0-litre TDI diesel engine.

Usefully, the spread of power is very broad - at 3,000rpm (a speed that will be achieved much more often than peak power figure of 5,500) the S5's engine is already able to produce more than 230bhp. The sound of the engine matches the way it's being used very nicely. In normal motoring it's quite subdued, but it produces a satisfying road when you're heading towards the red line at full throttle.

While some driving enthusiasts may be disappointed that you can't have an S5 with a manual gearbox, the S tronic unit (known elsewhere in the Volkswagen Group as DSG) is excellent, changing from one ratio to another smoothly and very quickly.

Ride and Handling

The handling is very secure, and you can push on quite hard through corners when conditions and circumstances allow.

When fitted with the optional drive select system, the S5 has three driving modes - Dynamic, Comfort and Auto - which apply to the suspension, engine mapping, gearchange points, differential and steering power assistance. As far as the suspension is concerned, we like Dynamic best, not because it makes the S5 especially sporty, but because it keeps a check on body movement which quickly becomes excessive if you choose the Comfort setting. In Dynamic, wallowing is reduced to a minimum, and the ride quality remains very acceptable - far better, in fact, than it is in many other quick Audis. The handling is very secure, and you can push on quite hard through corners when conditions and circumstances allow. It's never exciting, though. With either more power or less grip, the S5 would be much more thrilling than it is now. The actions of all the major controls are firm and precise, and will be immediately familiar to anyone with previous experience of medium-sized Audis.

Interior and Equipment

Audi introduced the supercharged 3.0-litre V6 engine as a replacement for the 4.2-litre V8 used in the previous-generation S4.

As the flagship of the A5 Sportback range, the S5 has plenty of equipment as standard, including leather upholstery, climate control, DAB digital radio, cruise control, automatic tailgate opening and floor mats. The last of these features is frequently an extra-cost option in Audis. For a little over £1,000 you can have the S5 Black Edition. In addition to various dark styling elements, this has a Bang & Olufsen audio system with Audi Music Interface and a stylish if not particularly useful flat-bottomed steering wheel. Like other A5 Sportbacks, this one has a luggage capacity of 480 litres up to the parcel shelf with the rear seats in place and 980 litres to roof level with the seats folded down. The seats have a through-load facility in case you need to carry long objects. The leather sports seats feel very well made and comfortable. One downside, however, is that legroom and especially headroom at the back is tight for adults.

Cost

The S5 is the most expensive version of the A5 Sportback and will certainly be the most expensive to run.

The S5 is the most expensive version of the A5 Sportback (though the 3.0-litre TDI comes within about £2,000 of it) and will certainly be the most expensive to run. Combined fuel economy is officially 36.7mpg, but something nearer 30 is more likely in real life, while the CO2 emissions are 179g/km. Vehicle Excise Duty payments will therefore be £225 from year two onwards, while the Benefit In Kind rating is 28% until April 2015 and will rise by 2% in each of the next four financial years. With no extras fitted, the S5 has a list price a little under £44,000. That's not the end of the story, though, because there are so many styling, technical and equipment upgrades that you could easily find yourself spending a further £10,000.

Our Verdict

Unlike other fast Audis, the S5 Sportback is soft and friendly, the ride is generally comfortable. It's also good fun in corners and can accelerate hard in a straight line, and the combination of these abilities and the practicality of the Sportback bodyshell makes the S5 a tempting proposition. All the same, it has a very serious rival, and Audi builds that too. The A5 Sportback with the 3.0-litre TDI is nearly as expensive but will be cheaper to run and is nearly as quick, with even better performance at lower speeds. It also sounds great. This particular A5 model is therefore easier to recommend than the S5, unless you're really desperate for the extra power and slightly sportier styling.