The Brera's central differential is a Torsen C that encloses the front differential for the first time, a solution that ensures considerable benefits in terms of dimensions, weights and also performance. It exploits the forces set up by the front differential to increase its locking effect (35% during traction and 45% during release) to set up a self-locking effect on the front differential as well (up to 20%). The consequence of this is improved traction and cornering stability.


The basic torque distribution of the Q4 system is mainly to the rear (43/57) for greater sportiness. Due to its locking effect, the central differential is able to send drive torque to the axle with the best grip on the ground moment by moment. This allows the system to switch from the initial torque distribution pattern to a distribution pattern focused on the front (72/28) or a distribution focused on the rear (22/78) in fast, automatic and continuous manner according to the grip and slip levels of all four wheels. The Alfa Romeo Q4 four wheel drive system implements permanent, dynamic torque distribution over all four wheels to achieve the highest levels of active safety and sportiness. The Alfa Brera Q4 is four wheel drive Alfa Romeo style: an essentially mechanical system complemented by the most advanced electronics to assure maximum driving comfort together with optimum performance and total safety.

The vehicle is absolutely cutting edge as far as engineering is concerned and offers significant benefits:

• Alfa Q4's four wheel drive with advanced Torsen C self-locking differential (Twin Diff.) makes it possible to achieve improved roadholding, driving satisfaction and smooth responses.
• Preferential distribution to the rear axle also adds to driving satisfaction because it makes the car easier to handle while ensuring maximum stability when the car suddenly veers at top speed on the motorway, as can happen during emergency manoeuvres.
• The ability to travel safely in poor grip conditions without the aid of electronics in torque split for constant driving satisfaction.

Tyres and pressure sensor

The excellent on-road behaviour of the Alfa Brera is also aided by its tyres that achieve the best possible compromise between handling and comfort. To guarantee a controlled drift on corners, combined with an excellent capacity to absorb obstacles, the Alfa Romeo engineers and their suppliers have developed special larger tyres, up to 235/45 R 18. In addition, from 2006, the Alfa Brera will also feature a tyre pressure sensor that signals any anomalies by a buzzer and a message on the display.



Braking system

The system is the most competitive in its class and upholds Alfa Romeo tradition in this field. The power-assisted, hydraulic system comprises two cross-over independent circuits, and is particularly effective, guaranteeing prompt, smooth braking combined with minimal stopping distances. The system naturally differs according to the engine version (in terms of weight and power): vehicles equipped with the 2.2 JTS are fitted with 305 mm self-ventilated discs on the front wheels and cast iron floating calliper with piston; the rear brake discs are solid (278 mm diameter) while the calliper is aluminium with a piston.

The powerful Alfa Romeo Brera 3.2 JTS Q4 is fitted with 330 mm ventilated discs with a four piston monobloc aluminium calliper on the front wheels; a 292 mm disc, also ventilated, with a floating calliper on the rear wheels.

This vehicle marks the first application of a monobloc aluminium calliper with radial attachments to the front brakes of an Alfa Romeo: this option increases calliper stiffness without increasing the weight and therefore makes for increased performance, particularly during a sporty drive.


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