Alfa Romeo's new Q2 self-locking front differential, which improves all the strong points of a front-wheel drive system in terms of active safety, increasing driving enjoyment and control, has arrived on the market. The innovative system provides some of the advantages typical of four-wheel drive, but at a significantly lower cost and weight. The system is now available exclusively with the 150 bhp JTDM engine on the Alfa GT and Alfa 147, but will subsequently be extended to other models in the Alfa Romeo range. It is a step forward that reflects the current state of the art of turbodiesel technology which, since 1997, the year that the Alfa 156 JTD was launched (the first car to adopt Common Rail technology), has seen a considerable increase in torque delivery to the wheels even on compact cars. Alfa Romeo has developed the sophisticated ‘Q2’ system to guarantee maximum control and traction in all driving conditions.

In addition to the new transmission, the Alfa 147 ‘Q2’ is also identified externally by a number of stylistic details: satin finish whiskers, grille and mirror housings, special 17” alloys, a rear spoiler, chromed exhaust terminal, lower stance and the ‘Q2’ logo at the rear. Inside, this version has a particularly sporty outfit underlined by 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. The equipment of the Alfa 147 ‘Q2’ is completed by radio controls on the steering wheel, cruise control, the VDC system, 6 airbags and a Bose® Hi-Fi system.

The Alfa GT ‘Q2’ version, on the other hand, has specific 18” rims, dual chromed exhaust terminals, satin finish grille, whiskers and mirror housings, low stance and the ‘Q2’ logo on the tailgate. The styling of the interior underlines this version’s sporty character: an instrument panel with a red background and white lighting, black leather seats with red stitching and the Alfa Romeo logo, the steering wheel, gear lever and handbrake gaiters in black leather with red stitching, special ‘Q2’ heel-high strips, grey anthracite facia trims and aluminium pedals. And finally, radio controls on the steering wheel, radio with CD and MP3 player, and a Bose® Hi-Fi system with sub-woofer are all standard.

The introduction of the ‘Q2’ versions of the Alfa 147 and Alfa GT extends the range of the two models which are enjoying great popularity with public and critics, not only achieving their set goals but exceeding every expectation. For example, in almost three years on the market, the Alfa GT has acquired over 55,000 customers in Europe, which underlines that the model has earned itself an important space in a fiercely competitive market segment.

The Alfa 147 is even more successful; since 2000, more than 500,000 have been bought by European motorists. And we cannot overlook the accolades from the trade press which, to date, has awarded the car a total of 32 prizes, acknowledging the car’s ability to express a new concept of sportiness in which elegance, comfort, safety and refined technology converge. Prizes from the critics include: the title of ‘Car of the Year 2001’, ‘Volante d’Oro’, ‘Trophées du design 2000’, and ‘Auto importado del Año en Brasil 2002’; while those awarded by readers include: ‘Auto Europa’ in 2001, and ‘L’auto che preferisco’ in 2001, 2003, 2004 and 2005.

The Alfa 147 and Alfa GT have kept their promise, achieving important goals. The merit certainly goes to the sound foundations on which the models are built: the best elements of Italian design, sophisticated engineering and the many engine-gearbox combinations which have been constantly updated and added to, maintaining public interest high at all times, as the debut of the ‘Q2’ version today underlines.

How the Alfa ‘Q2’ system works

Combined with the exclusive double wishbone front suspension, the system allows very effective fine tuning of the car. Alfa Romeo started from the excellent reputation that front-wheel drive enjoys with customers (in fact it is the layout chosen by the majority of car-makers). Suffice it to say that, in addition to the overall benefits of this type of architecture (weight, roominess, etc.), in extreme conditions, the understeer typical of front-wheel drive enables the driver to respond more intuitively to the car’s reactions: this gives the impression that front-wheel drive is more ‘responsive’ than rear-wheel drive. To highlight these benefits, Alfa Romeo has developed the ‘Q2’ system which embodies all the strengths of front-wheel drive, significantly increasing roadholding, traction and stability on the release, while attenuating understeer on acceleration, the intervention of the electronic control systems and steering wheel vibration.

The two practical examples below highlight the technical potential of the ‘Q2’ system.

Case no. 1: when the car corners

Taking a corner when grip is poor (wet road, snow, mud, etc.) or with a sporty driving style, grip is often lost on the inside wheel. When the transfer of the lateral load takes weight off the suspension, torque on the inside wheel is reduced, and a conventional differential (which splits the same torque value between both wheels) transfers an equal amount of torque to the outside wheel, but this is insufficient for good traction.

In this situation the car can respond in two different ways, depending on the equipment mounted. On a model without ASR-VDC, the perceived result is the slipping of the inside wheel, a loss of control of the car (strong understeer) and a loss of acceleration coming out of the bend. If, on the other hand, the car is equipped with ASR-VDC, the intervention of the driving assistance systems takes power from the engine, acting on the throttle valve and the braking system, so that it becomes impossible to modulate the accelerator, producing the unpleasant sensation of a drop in power. In both cases, the result is that as the car comes out of the bend, the driver has the feeling that it is ‘stationary’.

What happens when the ‘Q2’ system is present? When the inside wheel starts to lose grip, torque is partially transferred to the outside wheel, producing less understeer, greater stability, and increasing cornering speed. The improved mechanical efficiency of the ‘Q2’ transmission delays the intervention of the vehicle control systems, guaranteeing better traction as the car exits the bend, which makes driving more enjoyable and maintains complete control of the vehicle.

Case no. 2: surfaces with poor grip

On surfaces with poor grip, it is quite common for the drive wheels to have different degrees of grip. For example, grip under the two wheels can differ on snow-covered or wet roads. In these conditions, starting off or accelerating sharply could cause the wheels to slip, generating critical friction conditions, a strong reaction on the steering wheel, and inadequate take-off, making it necessary to correct the steering-wheel continuously to maintain the trajectory.

What happens when the ‘Q2’ system is present? The negative effects are attenuated by the gradual transfer of torque to the wheel that can exploit the best friction coefficient, simplifying a hill start, for example, and making driving on all roads with changing surface conditions safer and more comfortable.