Audi TT RS

BBC1's 'Ashes to Ashes' made the 1980s classic cool again, but this remake has more front than style

Ashes to Ashes has finished and Monday evenings won't be the same. For one thing, there will be no more bright red Audi Quattro slithering and smoking across our screens.

But here's a cure: another bright red Audi Quattro. It has all the ingredients: coupé body, four-wheel drive and – vitally, because it creates the right soundtrack – a five-cylinder turbo engine. Meet the Audi TT RS, fitted as standard with quattro drive and bearing a small "q" because here, as with all other all-wheel-drive Audis since the demise of Gene Hunt's weapon of choice, quattro is a system rather than a model name.

Making it into an RS alters the TT's personality dramatically. Its price, too – at £42,985 for the Coupé and £44,885 for the Roadster – is well into Porsche Cayman territory. However, the tuneful, harmonic hum of those five cylinders and the promise of 340bhp from its 2.5 litres might justify the cost. And if the glory days of the 1980s Quattro can be rekindled, then the makeover will have been worthwhile.

There are fundamental differences between the TT RS and the "Huntmobile". The TT can't accommodate two fully-grown people in its rear seat, let alone two plainclothes officers, because it's a smaller, daintier car. And its engine is mounted transversely rather than lengthways. Cylinder-count and turbo presence apart, nothing is shared between the engines; the TT RS's engine block is the same as is used in US versions of the Volkswagen Jetta, and the cylinder head is closely related to those used in a Lamborghini Gallardo or Audi R8 V10.

Like those cars, the TT RS sounds delicious. Pressing a "sport" button opens a bypass valve in the exhaust system to release a deeper, louder note as well as hastening the accelerator's response; this is becoming the usual way to make a car sound fruity while meeting noise regulations. Actually, the bass boom of the sportified exhaust gets wearing, and there's no power gain at lowish speeds to justify the pain. At high engine speeds, when the valve is really needed, it opens automatically anyway.

Do you sense a triumph of presentation over substance? There's more. The TT RS has a rather flamboyant rear spoiler, a veritable wing more suited to a racing car. You would think it would increase downforce at speed, but it turns out the design brief called only for something to give as much downforce as the standard TT's discreet, retractable spoiler. "Actually it gives slightly more," says Stephan Reil, the development manager of Audi's specialist Quattro division, "but you can't feel it when you drive."

Then there's the matter of the speed limiter. Normally this is set, as is common in the fast-car industry, at 155mph. But if you feel the need, and have the opportunity, to go faster, which the TT RS is quite capable of doing, you can spend something over £1,000 and have the engine's management chip reprogrammed to 174mph. It would be the matter of minutes to do this, but at least your engine bay will gain a carbonfibre 'dress-up kit' to give more substance for your cash.

All right, the TT RS is very rapid. It can hurl itself from a standstill to the standardised 62mph in 4.6 seconds, and, being turbocharged, it has terrific pulling ability without the need for the crankshaft to spin at huge speeds. Spoiler apart, it looks muscularly neat with its hunky wheels, racy front and rear valances, and ample front air intakes – and the true enthusiast will be pleased that a six-speed manual is the only gearbox offered. Then there is the promise of satisfaction on twisting roads, because the quattro system is recalibrated to allow a majority of the engine's efforts to be directed to the rear wheels much of the time.

That philosophy was applied to the S4 and S5, too, and those cars are among the most driver-pleasing Audis of recent times. Oddly, it doesn't work in the TT RS. It didn't help that the car I drove on the Zolder racetrack in Belgium, chosen to allow limits to be explored, didn't allow the traction and stability control to be fully freed-off even though a racetrack is where you need that freedom most. So it simply felt like a very fast, very grippy but rather inert, nose-heavy car with front-wheel drive. Of the little power-flourishes of the tail on exiting a bend, which the S4 and S5 do so well, there was no sign.

The TT RS, sad to say, seems a backward step in Audi's development of dynamics, a return to the dull days of speed without thrill or engagement. A Volkswagen Golf GTI, with similar underpinnings, less power and front-wheel drive only, is much more fun. So, crucially, is a Porsche Cayman S.