AT first glance the Audi S1 doesn't really strike you as being a high performance car, probably because it looks so much like the A1 family hatchback on which it's based.

But look closely and there are a few, admittedly discreet, little tell tale signs.

For starters there's the red-backed S1 badge on the boot and grille and the "face" of the car is slightly more aggressive. And if you happen to look below the rear bumper you will spot four exhausts instead of the conventional one protruding out.

But overall this is not a car which shouts about its motoring prowess - until you turn the ignition key.

In the first few minutes behind the wheel you suddenly find that this "family hatchback" has a wicked side and is one of the fastest small cars on the road.

Beneath the bonnet beats a 231bhp turbocharged, four-cylinder petrol engine which rockets this three-door, four-seater to 62 miles per hour in just 5.8 seconds and on to a top speed of 155 miles per hour.

If ever the name pocket rocket was made for a car it's the Audi S1.

And in many ways the blistering performance in the low gears seems even more dynamic because this car is so compact, being the smallest in the Audi range.

But all that power isn't a lot of good if you can't put it onto the road cleanly, without wheel spin.

Which is why the S1 has Audi's four-wheel-drive quattro system on board to put the power through both axles.

Being a quattro means this car has superb grip and road holding to ensure that you can safely get fun out of all that power.

Normally the S1 operates with 60 per cent of the power going to the front wheels and 40 per cent to the rear but when necessary it can vary it up to 50-50.

And just to make it more enjoyable the car comes with drive select to allow you to determine when you want a firmer ride and more sporty throttle response.

Like the A1 this car is a four-seater rather than five but it's spacious enough and because of the high roofline getting into the rear seats when you only have two doors is not a problem.

Boot space, however is somewhat limited at 210 litres. While it will cope with the weekly shop you will definitely struggle with suitcases unless you lower the rear 60/40 split rear seatbacks.

Inside the S1 you get high body hugging sports seats - which, in the case of my test car, were in nappa leather with S1 embossed into the front headrests for an extra £650 - a flat-bottomed chunky leather sports steering wheel and typical Audi functional rather than flashy dashboard in black with elements of contrasting brushed aluminium.

Cruise control and air conditioning are also standard, the latter being essential as the rear windows in A1/S1 models don't open.