AS I rounded a corner, I was confronted with a mini river pouring across the road, and there was no time to do anything except curse myself. I gripped the steering wheel, kept my foot in and waited to see what happened.

The result? Absolutely nothing. The A3 just beat through it with no shimmy, slip or slide. It was as though the torrent wasn't there.

Fitting the Quattro system to the 1.9 TDI 130 Sport A3 has produced a car that will sprint with the best of them and glues itself to the road. On a twisty country lane the combination of huge all-round diesel surge combined with tremendous levels of grip means the A3 is a pocket rocket that is wonderfully understated.

The great thing is that in a corner, a driver can keep on the power knowing that it will come out the other side composed and still accelerating.

The 0-62mph time is only 9.1 seconds, probably because the first couple of gears are so short and time is wasted in the changes, but it is much faster than that through the six gears when the huge amount of torque – 228lb-ft at 1,900rpm – can really get it going.

One gripe would be that when it is being pushed, the A3 requires a lot of gear shifting because it peaks in each gear very quickly. I'm sure that one day a really great semi automatic gearbox will make a six-speed diesel car like this absolutely fantastic fun. The car has the fit and finish you would expect of an A3, an excellent driving position and a top quality feel all round.

A potential downside of the Quattro system is that it piles on the CO2 substantially. A front-wheel drive A3 1.9 TDI emits 138g/km, while the Quattro balloons to 162g/km, although this is still below the 165g/km minimum threshold for benefit-in-kind tax purposes.

With a P11D price of £19,915 and CO2 emissions of 162g/km, the Quattro version will cost a 40% tax-payer £1,434 this year.

Fuel economy is down with the effort of driving the extra wheels, from 52.3mpg for the standard model to 44.8 for the Quattro.

Less money is also lost in residual values on the front-wheel drive car, with CAP estimating it will be worth £7,600 or 43% of its cost new after three years and 60,000 miles, while the Quattro retains £8,450/42% over the same period.

But there is no doubt that the huge grip of the Quattro system is a fantastic safety valve for the A3, and all other Audis.

It comes at a cost to the driver of about £200 a year in tax over the front-wheel drive model. But at less than £20 a month, it has to be a worthwhile price to pay for the extra security it brings.

Model: Audi A3 1.9 TDI 130 Quattro Sport
Price (OTR): £20,090
Top speed (mph): 126
0-62mph (secs): 9.1
Combined economy (mpg): 44.8
CO2 emissions (g/km): 162
CAP Monitor residual value (3yrs/60,000 miles): £8,450/42%
Service intervals: variable
Warranty: 3-years/60,000-miles