Torque can easily corrupt. Especially if there's a lot of it and it's being directed to a pair of front wheels, as is the case in this 150bhp Alfa Romeo 147 diesel. Granted, 150bhp doesn't sound an unmanageable power output but again we come back to that torque figure. This car generates some 225lb/ft of torque, which is about what a performance coupe like a Honda NSX or a Porsche Cayman is being asked to put through its rear wheels. When a car accelerates from a standstill, the weight transfer is such that it squats on its rear wheels, leaving the front pair scrabbling. Suddenly, you realise the challenges facing the manufacturers of muscular front wheel drive models. Alfa thinks it has come up with a solution with the 147 Q2 model.

One of the most difficult traits to eradicate in a car of this type is torque steer. This occurs when a powerful front wheel drive car is asked to deploy all that grunt, and the resultant effect is the car 'weaving' its way up the road as first one wheel, then the other achieves grip. It's hardly elegant, and the tugging steering wheel can be unsettling if you're not quite sure what's happening. Radical redesigns of some cars' suspension systems to equalise the lengths of the half-shafts supplying drive to each wheel can be a solution but this isn't a fix that can be applied to a model halfway through its life. Alfa Romeo has instead opted for the best available remedial solution for the 147 Multijet 150, the installation of a Torsen limited-slip differential. Prices start at £16,950 and include high value 'Sport' trim.

This torque-sensing differential works by limiting the amount of slip to one wheel. In simple terms, it directs more drive to whichever wheel is moving slower, the inference being that the slower wheel has grip and the quicker wheel has lost it and is spinning freely. The effect is that there's a cleaner, more natural feel during cornering. Drive the old 147 Multijet 150 hard through a corner and as soon as the turbocharger started reaching peak torque, it would overwhelm the front wheels and power would be directed to the inside front wheel which would then just spin impotently in a haze of tyre smoke. Most frustrating. With the Q2 system, the outside front wheel gets the lion's share of the torque split and uses it to good effect, driving the 147 purposefully through the bend with less throttle modulation or sawing at the wheel to try to get meaningful drive back.

"The Q2 system civilises the Alfa's power delivery quite considerably"

It always seemed a shame that such a brilliant engine created such handling issues but thankfully that's behind Alfa now and the engine's still a cracker. The Multijet system takes the idea of pilot injection - squirting a small amount of fuel into the cylinder to 'prime' the combustion chamber for the main ignition process - and refines it still further. In this instance, the main injection is divided into a series of smaller injections, allowing smoother, more gradual combustion that utilises fuel more efficiently. The electronic control units have to be astonishingly precise to achieve this. Whereas before the time lag between injections was a relatively yawning 1,500 microseconds, the response time has been slashed by a factor of 10. A variable geometry turbocharger and a high pressure direct injection system make the 150bhp output possible but the key is a torque output that makes the 147 Q2 feel gutsier than the old 250bhp 3.2-litre V6 147 GTA model.

You'll believe that too when you drive the car. Fire it up and the engine settles into an unobtrusive background thrum that never threatens to rattle the expensively moulded dashboard. Yes, you can tell its sups from the black pump, but it's hardly what you'd describe as coarse. On the move the engine remains pleasantly muted without the whistles and bellows of many powerful turbodiesel cars. Between 1,750 and 3,250rpm, there's a huge shove in the back, the elastic power delivery catapulting the Alfa down the road in a deliciously addictive manner. Even in sixth gear, the 147 Q2 will dispatch the 50-75mph increment in just 7.9 seconds. From rest, it will accelerate to 60mph in 8.8 seconds and run on to a top speed of 129mph. Average fuel economy is pegged at 47.9mpg and emissions amount to a mere 157g/km.

Despite featuring classic cowled fascia dials, the 147 also encompasses some determinedly high-tech touches. Six airbags come as standard, as does dual-zone climate controlled air conditioning. State-of-the-art multiplex wiring has made possible the option of a full-screen voice activated satellite navigation system with an inbuilt Bose stereo and GSM telephone system. It's not cheap, but the satellite navigation setup is one of the best available anywhere, as is the Vehicle Dynamic Control, which is a stability control system designed to prevent the 147 spinning. It's on a par with the PSM program used by Porsche in the way that it credits the driver with some leeway before gently stepping in to restore equilibrium if progress is overenthusiastic.

In addition to the drive system, the Alfa 147 Q2 is also identified externally by a number of styling enhancements: satin finish front end detailing, grille and mirror housings, 17-inch alloys, a rear spoiler, chromed exhaust finishers, a lower stance and the 'Q2' logo at the rear. Inside, this version features instruments with red scale background and white lighting, leather upholstery with red stitching on the steering wheel, gear lever and hand brake gaiters. Grey anthracite trims on the steering wheel and central console, special 'Q2' heel-high strips and aluminium pedals complete the effect. There's also stereo controls on the steering wheel and cruise control.

It's probably too late for the 147 to go down as one of the all-time great hatchbacks but it's still a very stylish contender and the Q2 system makes a brilliant powerplant all the more accessible. In short, it's well worth consideration.