Tarraco takes on North Africa

The SEAT Tarraco 4Drive rises to the Moroccan challenge


Inside 4Drive

The Tarraco benefits from one of the safest, most efficient and advanced on-demand all-wheel drive systems in the world: 4Drive. The latest generation multi-disc traction system uses hydraulic operation and electronic control to deliver power to the wheels in a controlled manner, maximizing traction.

Located on the rear axle, the system sits at the end of the drive shaft, just in front of the rear differential. This gives two benefits: the first is improved weight distribution; the second is a reduction in inertia and system reaction time because the cardan shaft is always connected to the engine.

The multi-disc wet clutch features metal friction rings placed in pairs, one in front of the other. One ring of each pair is permanently connected to the drive shaft that turns with the gearbox, the other ring turns with the driveshaft joined to the rear axle’s differential. A hydraulic actuation piston compresses the multi-disc packet to reach the required oil pressure, depending on the parameters indicated by the electronic control system.

To make up for small variations in length generated by flexing in the elastic elements that hold both axles, there are two flexible joints at both ends of the drive shaft and a sliding sleeve in the centre.

Because there’s need for a pressure accumulator the system is lightweight but benefits from an improved response time, bringing considerable active security and dynamic advantages.

SEAT’s on-demand 4Drive technology improves efficiency too. The Tarraco works just like any other front-wheel drive vehicle in normal driving conditions, allowing the drive shaft that sends power to the rear axle to rotate freely, reducing resistance. But should conditions become more challenging the rear axle engages as soon as the system detects the front wheels slipping delivering power instantly to the rear wheels. The advantage of this approach is that it ensures excellent power delivery when it’s needed, but keeps any increase in fuel consumption and emissions to a minimum.

When engaged, the intelligent 4Drive system can adjust the driving torque delivered to each axle, equal distribution between the front and rear (50% - 50%) and can even send all the power to the rear axle instantly. As well as this, 4Drive makes torque distribution variations possible between one wheel on one side or the other. The conventional front and rear differentials use an electronic aid, EDS, a simple and light solution that is efficient and safe, and means no transversal torque is lost as the system locks the slipping wheel relative to the opposite side.

4Drive is capable of analysing grip levels, vehicle load, speed, steering wheel position and driving style in real time to deliver power quickly and progressively to the required wheel or wheels, meaning you always have traction, control and responsiveness when it’s most needed.

The SEAT Tarraco is also equipped with the progressive steering (standard in Xcellence trim).  Compared to a conventional steering system, the progressive steering is based on a progressive steering ratio. In addition to offering a significant angle reduction while maneuvering or parking, the progressive steering offers a much more dynamic response on curvy roads.