2013 The new Toyota Corolla DPL: Driving performance
- Increased use of high tensile steel for a lighter, more rigid bodyshell to promote improved ride comfort and vehicle agility
- Revised front MacPherson and rear torsion beam suspension for improved ride comfort and enhanced steering response
- Optimised, more rigid Electric Power Steering (EPS) system for reduced vibration and enhanced response
The new Corolla has been engineered to offer customers a more enjoyable and involving driving experience.
As previously highlighted, the Corolla features a longer wheelbase, a lower centre of gravity through an overall reduction in height, improved aerodynamic performance for greater high speed stability, a lower, more engaging driving position and a new Multidrive S CVT gearbox incorporating a sport-mode.
The new Corolla further benefits from a lighter, yet more rigid body structure, revised suspension and a more direct steering response.
Lighter, High Rigidity Bodyshell
The increased use of high tensile steel throughout the body structure has allowed for the adoption of a lighter metal in several areas, its increased strength offering a weight saving of some 5.7 kg per vehicle with no detriment to overall rigidity.
Overall bodyshell rigidity has been enhanced through an increase in the number of body spot-welds, a coupling of the front suspension spring supports with a straight-shaped cowl front, an improvement to lateral rigidity within the underbody, and an increase in structural rigidity around the back panel.
These measures combine to contribute to both excellent ride comfort and improved response to steering inputs for greater agility.
The new Corolla shares the proven front MacPherson strut and rear torsion beam suspension systems of its predecessor. Significant revisions to both front and rear systems promote improved ride comfort combined with greater agility.
A newly developed front strut features a larger, 35 mm diameter shock absorber cylinder, with damping force tuned to optimise stability and ride comfort. The length of the urethane bound stopper has been reduced to accommodate the strut within the lower vehicle height, and a solid input type upper support has been adopted to reduce high frequency vibration and enhance steering response.
The coil springs feature a pigtail structure at either end for a compact, lightweight installation. Coil spring reaction force is controlled by adopting a lateral force reduction spring, and suspension friction has been lowered by reducing the bending force on the shock absorbers.
A reduction in the rotational force on the strut bearings achieves a light and responsive steering feel. And an increase in bodyshell stiffness has allowed for a reduction in the coil spring rate, enhancing ride comfort with no detriment to steering response and handling agility.
Featuring independently located coil springs and dampers to minimise loadspace intrusion, the lightweight rear torsion beam suspension also benefits from solid input type upper supports, urethane bound stoppers and pigtail coil springs. A reduced spring rate and retuned dampers further improve ride comfort, stability and response to steering inputs.
Sharper Electric Power Steering (EPS) Response
In conjunction with a lowered column angle designed to offer drivers a more involving driving experience, the new Corolla's EPS system has been revised. The power steering gear specification has been optimised and its rigidity enhanced to give a sharper steering response and smooth, linear operation.
System rigidity has been improved through structural changes to the intermediate shaft and the rigid attachment of the steering gear box to the suspension member, creating a more direct, linear steering feel. A revised upper column support further reduces unnecessary vibration.
The system now features an integrated ECU with a new control logic to improve steering feel, and the ratio of the steering gear itself has been lowered from 15.9 to 14.6 making it 8% faster than its predecessor to promote a sharper response to steering inputs.