WHEN Italian car maker Alfa Romeo wanted to add a little kudos to its high performance Giulia Quadrifoglio executive saloon it knew where to turn - fellow high performance Italian brand Ferrari.

So it's hardly surprising that a car with an engine developed with the help of the legendary prancing horse brand is one of the fastest on the road today.

In fact in terms of acceleration the Quadrifoglio is just a fraction of a second slower than some Ferrari models.

But with a twin-turbo 2.9-litre V6 developing 510 bhp under the bonnet it's perhaps not surprising.

Yet despite its blisteringly quick performance this 191 miles per hour car is surprisingly restrained in appearance, if you don't count the massive quad exhausts protruding from the rear.

There are other visual features which distinguish it from the standard 2.0-litre model - which is less than half the price - including bigger wheel arches shrouding the dark 19-inch alloy wheels, lowered suspension and deeper bumpers front and rear but it's all reasonably discreet.

The only obvious clue to the performance of this low, sleek Italian supercar are the two white triangles with green clover leafs on them on the wings.

The badges give it Quadrifoglio (Italian for four leaf clover) status, and to anyone who knows the brand that means performance with a capital P.

So much so that this tour de force saloon has won the What Car? Performance of the Year award for the last three years in a row.

You only buy the Giulia Quadrifoglio for one thing - power.

With a 0-62 miles per hour time of just 3.9 seconds it's like a rocket ship on wheels. Turn the Alfa's dna driving mode selector from normal to dynamic ( the a is for "all-weather" mode), put your right foot down hard and if you don't hang on to the steering wheel you could end up in the back seat.

But good as dynamic mode is there is one further step on the drive selector; race mode.

Engage this and the exhaust note suddenly becomes louder and more intense, the traction control is turned off and you get a message telling you it's best to switch from the eight-speed automatic gearbox to manual gear changing.

It's good advice if you want one of the most exhilarating experiences on the road today.

It's not for the faint hearted but if you grasp the nettle the Quadrifoglio shows just why people are prepared to pay upwards of £67,000 to own one.

This really is thrill a minute motoring with the Alpha's exhausts crackling and barking on every gear change as the car heads for the horizon at breakneck speed. I've driven quicker cars but I really can't remember when.

As it's rear-wheel-drive you have to be wary with all that power going to the back end but in truth the traction is so good it's easily controllable unless you really take liberties.

And the nice thing about this supercar is that in normal mode the adaptive suspension ensures it's a superbly comfortable every day car that cossets you with a compliant ride and creature comforts like heated seats and a heated steering wheel.

The impressive interior features a lush mix of black leather and Alcantara on the seats, doors and dashboard with contrasting red leather stitching. And the red launch button - sorry starter button - dominates the leather covered steering wheel as do the oversized paddles for manual gear changes.

And is case you forget the racing heritage of the Quadrifoglio there's a tiny plaque near the gear shift in the colours of the Italian flag.

Despite it's high performance prowess the Giulia Quadrifoglio offers sensible economy. During a week's motoring I notched up and average of just over 25 miles per gallon.