AUDI is taking its TT roadster and coupe into supercar territory with new range -topping RS models.

At £51,800 for the coupe and £53,550 for the roadster, the RS is some £20,000 more expensive than the basic TT - but this one is in the same league as Audi's mighty V10 R8 and that will set you back more than £110,000.

The new TT is the quickest Audi RS model ever and can smash the 0 to 60 barrier in just 3.7 seconds on its way to a theoretical maximum of 174mph.

But enough of the figures, of which there are plenty. What the TT RS is really about is extremes - extreme performance, extreme ability and extreme fun.

Out on the Jarama race track just to the north of the Spanish capital, Madrid and scene of some epic Grand Prix tussles in the 1970s involving legends such as Gilles Villeneuve, Jacques Laffite and John Watson, the RS showed its mettle in no uncertain fashion.

The TT RS is no stranger to race car technology - blisteringly quick in a straight line yet agile and nimble through the tightest corners.

Grip is enhanced not just by quattro all-wheel-drive but also with a vectoring system which produces some unbelievable traction.

Just a glance at the cockpit reveals that this is a car out of the norm and one that is very special.

The starter button is mounted on the sports-style, alcantara covered steering wheel and sits opposite the car's drive mode selector - the button which releases maximum venom.

Switch the virtual instrument panel into RS mode and the information is all track related. Dials for the power, torque and G force and a lap timer replace the more conventional layout for the road.

Unleash the power - and there's 400 horsepower to go at - and the TT RS surges into life emitting a marvellous roar from its twin exhaust nacelles.

There's a ‘noise button' for added effect but the thrill of the chase is enough. The car is delightfully balanced and even close to the limits there's little load up on the steering.

Stopping power comes from high performance brakes - carbon ceramics are an option - and slick gear changes fire out of the seven speed dual clutch transmission either in auto mode or from the paddle shifters.

It's all honed for performance and enough to make the eyes pop on the most demanding of drivers. In every aspect the RS is as good as the R8 - just £50,000 cheaper.

The engine in the TT RS is a new take on the legendary 2.5-litre five cylinder block that powered the quattros of old. Not only does it sound so distinctive it is now turbo charged to the hilt giving the car a power to weight ratio of 277ps per tonne.

There's a fraction of lag as the RS takes off but if anything that helps its manners for everyday driving. Full bore arrives at 1,700 revs and from that point on the power delivery is relentless.

Top speed is restricted to 155mph but the RS can be unfettered by Audi Sport's technicians to release its full 174mph potential.

Magnetic ride is another option for smoother damping and the RS sits almost half an inch lower than a regular TT.

Huge air scoops dominate the lower portion of the nose while aerodynamics are assisted by flared sills and a boot mounted spoiler suspended on double struts. It can be replaced by a pop-up spoiler as fitted to other TTs as a covert touch.

Nineteen inch rims are standard, 20-inch wheels an option and the RS looks every bit the performance machine it is, set off with a honeycomb grille and some discreet badging.

At the back the TT RS is the first Audi to make use of organic LED (OLED) tail lamps which incorporate carbon coated elements to produce a stand out design complete with tiny Audi logos and TT legends.

The cockpit is fully connected including wi-fi and on the roadster Audi has fitted microphones into the seatbelt webbing to enhance speech quality when driving top down.

A Bang & Olufsen audio system is standard fit and so is leather upholstery embossed with the RS mark.

On the road the TT RS is as accomplished as they come. Not only is it quicker than the likes of the Mercedes-AMG SLC, the BMW Z4 and Porsche's Cayman and Boxster it also drives with great precision. Only the Porsche is a match in terms of all round dynamics.

The roadster is marginally slower 0 to 60 at 3.9 seconds and slightly thirstier. Audi claims an official fuel return of 34mpg with emissions of 189g/km while the coupe is rated at 34.4mpg (187g/km).

However, such economy is going to be optimistic given the car's craving for performance and enjoying it to the full we managed to achieve an average of just 18 to the gallon in the roadster.

A more sedate drive in the coupe realised close on 30 to the gallon. Both versions have stop/start systems to help out in traffic but this is a car whose forte is out on the open road.

Compared to the previous RS iteration of the TT, the new model is bigger and better all round, is slightly lighter and has boot space ranging from 305 to 712 litres in the coupe (280 litres in the roadster).

In every way it sets a new standard for Audi sports cars and is sure to become one of the most cherished high performance models to carry the four ring marque.