New SEAT León - In Depth

Press Release

Chassis: More agile than ever

Optimising the dynamic performance of the new León was a matter of overriding importance for the engineers at SEAT which is why they have once again opted for the renowned Agile Chassis developed by SEAT's own Technical Centre. Its integration into the new León required a meticulous fine-tuning process to further refine it compared to the version already featured in some of the brand's other models.

Each and every element that makes up part of the Agile Chassis has been revised and modified.  From the front and rear suspension through to the brakes, the steering through to the type of tyres and wheels, and the development of a new concept for the fuel tank through to the new pedal arrangement.

More effective suspension. The independent front suspension with McPherson struts is the same as on the first model, but it is now mounted on a new aluminium sub-chassis which replaces the sheet-metal version fitted previously. Agility has been enhanced as a result of the high centre of balance and an anti-roll bar with a diameter of 23.6 mm which has been made more effective by reducing the distance from the anchoring point to the centre of the wheel. Improvements have been made in terms of comfort too by optimising the axle kinematics, using a new wishbone mounting and separating the spring mounting from the shock absorber's mounting point on the body.

New rear axle concept. At the rear, the torsion axle (semi-independent) fitted in the outgoing León, has been abandoned in favour of an independent, four-arm multilink axle, which enables the longitudinal dynamics (comfort) to be handled completely separately from the lateral dynamics (agility). The result is an excellent standard of ride comfort combined with advanced handling agility. The rear suspension features an anti-roll bar with a diameter of 21.7 mm as well as shock absorbers and springs offering different tuning settings depending on the engine.

Optimised steering. The Technical Centre also undertook modification work to the car's steering. The new steering system is the EPS Electrical Power Steering system whose intelligent electro-mechanical design holds an array of benefits over the hydraulic power-assisted steering in the old León. Power assistance is varied to match the vehicle's speed and the steering wheel angle, bestowing the vehicle with extremely precise handling and outstanding responsiveness to the driver's commands. The new León offers two separate set-ups, one for the 1.6 petrol engine and a second fitted to the remaining engines.

Minor environmental impact. Due to the fact that power assistance is only provided when needed and not as a function of the engine speed, the electro-mechanical power steering produces tangible energy savings equating to 0.2 litres of fuel per 100 kilometres. It also features self-adjustment of the car's straight-line steerability and offers drivers direct yet gentle steering response. Dispensing with the hydraulic components reduces the impact on the environment, simplifies maintenance and lowers sound levels. Measures have also been implemented in order to optimise steering wheel damping when driving over rough road surfaces.

Increased safety. The design of the steering column has undergone further improvement to both enhance comfort and increase safety in the event of a collision. It offers the driver a reach adjustment range of 60 mm and a height adjustment range of 50 mm (51 and 36 mm respectively on the previous model), smooth, stepless adjustment and high resistance to vibrations. Both the housing and the lower shaft are telescopic. The steering column's upper housing can collapse by 100 mm and the lower shaft by 58 mm. Further features include an energy absorption system and impact-resistant steering lock.

New brake booster. The braking system in the new SEAT León comprises ventilated disc brakes at the front and solid discs at the rear wheels. The diameter of the front discs varies depending on the engine fitted. The discs fitted in conjunction with the 1.6 petrol and 1.9 TDI engines measure 280 millimetres across, while the two-litre powerplants (FSI and TDI) are partnered by 288-mm discs. The rear discs have a diameter of 255 millimetres on all models. The new León is equipped with a new dual-rate brake booster with two different characteristic curves: one offers comfortable, precise metered braking while the second provides high braking power by reducing pedal resistance when the driver needs to brake particularly sharply.

Wheels and tyres. Three different 16-inch wheel designs are available: a steel variant with hubcap, plus two light-alloy wheels, one with a five-spoke and one with a seven-spoke design. All 16-inch wheel variants measure 6.5Jx16 and are shod with 205/55 R16 tyres. There is also a 17-inch light-alloy wheel measuring 7Jx17 which is shod with a 225/45 R17 tyre.

Sophisticated ESP. Several key innovations have been incorporated into the Electronic Stability Program (ESP). The EDL Electronic Differential Lock, EBA Emergency Brake Assistance and O-HBV hydraulic pressure booster (for automatic models only) are now joined by a series of new systems:

·          Overboost, which increases brake pressure without any notable change in the force that the driver has to apply the brake pedal when the system temperature far exceeds normal operating temperatures.

·          BSW, which cleans the brake discs regularly whenever the windscreen wipers are switched on.

·          Driver Steering Recommendation (DSR) which helps to keep the vehicle on the correct course in critical handling situations.

·          Trailer Stability Program (TSP), a system which will become available in the future.

·          The Traction Control System (TCS) now includes an anti-lock braking system with Electronic Brake-Force Distribution (EBD) and ASR wheel-slip regulation.

Keeping on course. The most noteworthy of these systems is Driver Steering Recommendation. When the ESP control unit detects the vehicle has entered an unstable situation caused by oversteer, it transmits a signal instructing the steering system's electric motor to turn the steering wheel in the opposite, i.e. the correct, direction. The driver senses this as a recommendation, prompting him or her to turn the steering wheel in the recommended direction and stabilise the vehicle. When driving over a dry, asphalted road, the driver barely notices this steering prompt. The system proves most effective when driving along roads offering differing levels of grip on each side of the car, e.g. a surface that is dry on one side and wet on the other.

The principal benefits of ESP featuring Driver Steering Recommendation are improved stability, less directional deviation and a reduction in the vehicle's stopping distance of between 5 and 10 percent. However, the task of this are is merely to recommend a steering manoeuvre to the driver in critical driving situations. This function does not steer the vehicle for the driver, the driver is responsible for controlling the vehicle's steering at all times.

Bodyshell: High strength

As well as being attractive to look at, the technology behind the new SEAT León is no less beguiling, as is immediately evident from an analysis of the structure and mobile elements of the bodyshell which comes with a 12-year anti-corrosion warranty.

Special steels. The bodyshell of the new León comprises a unitised structure made from galvanised steel whose development entailed using 50% more high-strength and ultra-high-strength steels than in the previous León, resulting in far superior passive safety and body strength. 63% of the steels used are high-strength and a further 5% are ultra-high-strength. The sheet-metal components that together make up the top section of the body (roof, side panelling, pillars and side skirts) as well as the protective bars in the doors employ mostly high-strength steels, giving them excellent fracture resistance and a high elasticity limit. Similarly, the frame structure in the lower section of the new León is also composed of a high percentage of high-strength steels.

Hot pressing. One of the most significant technological innovations in the new León cannot actually be seen but it has greatly enhanced the level of safety offered in collisions from the side. It all has to do with the central B-pillar which, in addition to being built from ultra-high-strength steels, is furthermore manufactured using a hot-pressing process. This technology, which is being used for the first time ever at SEAT, dispenses with conventional pressing and replaces it with a combination of techniques, including heating the sheet-metal panel prior to drawing, drawing it into the press with a refrigeration system and finally laser-cutting the panel. This new process cuts down the number of different pieces used thus making the body more rigid, reducing the vehicle's weight and improving structural strength.

Laser welding. The tremendous static rigidity of the new León has been achieved by assembling the body using 5,100 mm of laser welding and 5,000 mm of structural bonding. Assembly furthermore involves applying 3,700 resistance-welding spots as well as 3,200 mm of arc welding. Thanks to the use of laser welding it has now been possible to eliminate the moulding that covered the join between the vehicle's flanks and the roof on the old León.

Quality control. Bodyshell assembly involves one further sophisticated process that deserves to be highlighted, the system for tracking the quality of the laser seam, known as Soudronic. Based on artificial vision technology, Soudronic supplies real time information on the quality of the laser seam being used for the assembly of the bodyshells, thereby guaranteeing the necessary process quality and stability.

Superior rigidity. The use of laser welding and structural bonding benefits both the static and the dynamic rigidity of the bodyshell in the new León. The car's high static rigidity is demonstrated by its interaxle torsion of 21 minutes of a degree when subject to a torsional torque of 7,000 Nm. As far as dynamic rigidity is concerned, the torsion mode is over 44 Hz, while the longitudinal flexion mode exceeds 46 Hz in the Z plane and 58 Hz in the U plane. The roof has also been made more rigid than on the outgoing model. Of the five cross struts that used to be fitted, the three struts at the two ends of the roof and in the centre have been retained, while the two intermediate struts that added 902 grams to the weight of the old León have now been omitted. They have been replaced in the new León by two DVD panels weighing a total of 446 grams, representing a weight-saving of 456 grams.

Better protected. The new León has been protected against corrosion by applying surface coatings, fine seals around the edges of moving components as well as thick seals. The underbody has been protected by a polypropylene guard that reduces PVC content by 1.2 kilograms, while the cavities are wax-protected. In order to reduce the levels of mechanical noise and tyre roar reaching the interior, as many as 10 soundproofing elements are incorporated into the upper and lower pillars, the rear wheel arches, the sub-platform side member and the pillar surrounds.

Passive Safety: For occupants and pedestrians alike

The new SEAT León is the first ever model from the Spanish brand which has the option to be fitted with up to eight airbags. Every model rolls off the production line with six airbags as standard: driver and front passenger airbags, side airbags in the front and two curtain airbags. These can then be supplemented by the new optional side airbags for the rear.

Up to eight airbags. Passive occupant protection in the new SEAT León is entrusted to the seat belts acting in unison with the six airbags (two front airbags, two front side airbags and two curtain airbags) fitted as standard in all the models in the range.  In addition to the standard airbags, two rear side airbags maybe added as an option.  This is the first time that the Spanish manufacturer has offered this feature in any of its models. The front passenger airbag may be deactivated by turning a lock inside the glove compartment using the ignition key. Upon deactivation an indicator lamp lights up in the instrument cluster showing that the airbag is not operational. It is important to stress, however, that all of the remaining airbags, including the driver's airbag, the side airbags (front and rear) and the curtain airbags, remain active after the front passenger airbag has been deactivated.

Securely fastened. All seats in the new León are equipped with three-point seat belts as standard, with the seats in the front also including pre-tensioners and belt force limiters, and the outer seats in the rear benefiting from dynamic belts including belt force limiters, with the vehicle's own centre rear seat being designed to function as a force limiter. An acoustic signal on the driver's side also sounds to remind passengers to fasten their seat belts if necessary.

Sensory system. Pressure sensors have been integrated into the front doors to shorten the response time in the case of side-on collisions. These sensors combine with the acceleration sensors in the rear wheel arches and the airbag control unit situated in the transmission tunnel to detect an impact from the side within just seven milliseconds. In the case of a collision, the airbag control unit triggers the seat belts and airbags as appropriate, as well as releasing the vehicle's central locking, shutting off the fuel pump and turning on the hazard warning lights and courtesy lights.

Greater safety for pedestrians. The front end of the new León has been specially designed to minimise the injuries caused to pedestrians in a collision.  The bonnet is capable of absorbing energy in a carefully controlled manner without losing any of its static or dynamic strength.  Its hinge is collapsible to further increase deformation capacity during the impact. In addition to this, the nose of the car crumples in such a way as to minimise the damage caused to the tibia, fibula, knees and hips, without increasing the costs for repairing the car following head-on collisions at low speed.

Protection for the smallest members of the family. The new León excels when it comes to child safety. SEAT has worked closely with child seat manufacturers to ensure that the child seat and car fuse together to form an integral unit that guarantees the highest possible level of protection for the smallest members of the family.