A DECADE ago it would have seemed fanciful to expect a family estate to crack the five second sprint to 60mph.

And the idea of nearly 350 horsepower under the bonnet would have been just as far-fetched.

But that's exactly what the latest Audi S4 Avant can boast. As well as exhibiting near supercar performance the five-seat, five-door exec is reasonable to fuel with the low 30s being within reach if you go softly.

Mind you, with a three litre turbocharged V6 at the front end, there's plenty of tempting reasons to avoid the constraints of frugality.

Mated to an eight-speed automatic gearbox and quattro four-wheel-drive, it's very much an iron fist in a velvet glove - acceleration though intense and sledgehammer-like is controllable and creamy smooth, accompanied by a cultured symphony of sound.

Nothing brutish or raucous here despite figures that wouldn't shame a Porsche 911 (0-62mph in 4.9 seconds). In fact the lighter body means that the latest car is just a fraction of a second slower than the last generation RS4.

An electronic speed limiter nudges in at 155mph to halt its relentless progress.

There are those who reckon Audi's quattro system diminishes the fun factor compared with a decent rear drive system. But I am not a subscriber to this view - you only need to have driven rapidly over a greasy road to realise the immense reserves of adhesion provided by a good all-paw set-up.

And the latest A4 models, built on a lighter platform, are noticeably more dynamic feeling and athletic than Audis of old.

It is surprising how well the S4 rides. Despite its firm suspension - the test car was fitted with optional adaptive sport suspension at £900 - there's ample upward movement which accommodates poor surfaces and protects passengers from jolts.

I found the Dynamic setting most impressive, while I reckoned that Comfort was too lethargic for a sporty Audi.

It feels composed and comfortable even when swift directional changes are made. The steering could pack a tad more feel, but that's a deliberate Audi trademark.

Some may find the S4's appearance rather sober. Certainly, its design is understated with only the deep front air-dam, two sets of oval tailpipes and a few badges to set the rapid Avant apart from its lesser stablemates.

But this Q-car impression is an advantage to those who don't want to attract attention.

And in practical terms, the S4 is just as roomy and sensible as most estate cars with flip-down rear seats, a regular-shaped boot that can easily swallow up all the family clutter, and the inevitable bevy of bottle-holders scattered around the cabin.

Trim and build quality is of the highest order with snugly fitting high-quality plastic mouldings, touch screen sat-nav with virtual cockpit and sports seats that hug you snugly.

Audi engineers have done well to make the S4 so efficient and reduce emissions to just 171g/km which equates with a combined fuel consumption of 37.7mpg.