Solid stable ride under any conditions
McPherson strut front suspension
Torsion beam rear suspension
Four channel hydraulic brakes
The high level of perceived quality and refinement of the new Chevrolet Sonic is realised when the car is actually experienced in a real-time driving situation when the full extent of the Sonic’s ride comfort, stability and handling become apparent.
The Sonic has been engineered to deliver a distinctly European flavour when it comes to driving dynamics. Sharp responsive handling combined with exceptional ride comfort place the Sonic at the head of its class. Equally at home on virtually all road surfaces, the Sonic provides excellent feedback in response to inputs from the driver. This is a fun-to-drive car that exhibits the dynamic characteristics of premium cars.
At the heart of the excellent driving dynamics is the taught and rigid body-frame-integral (BFI) structure at the core of the Sonic. This is the primary enabler for optimised chassis tuning and they key to the sense of driver confidence and being in command of the road that the Sonic imparts.
Add to this a stable footprint that comes as a function of the wheels-out stance of the Sonic with its four wheels placed at the outer extremities of the body. The wheelbase of 2525mm and track of 1509mm provide a lean athletic stance.
The inherent stiffness of the body structure is carried through to the suspension and drive train mounting points which are designed to match the stiffness of the body structure without any flex at these mounting points. The result is a chassis that proved easy for the engineers to optimise though suspension tuning but also one that is durable and provides a high degree of isolation from noise, vibration and harshness (NVH) intrusion into the passenger cell.
The Sonic features a McPherson strut-type front suspension with side-load compensated strut modules. The ‘flat-top frame’ axle is a no compromise design that ensures optimal stiffness in the frontal area of the chassis. This is essentially a straight axle without contours for packaging constraints. The flat top frame design enables a dynamically correct action and precise chassis component tuning together with effective control of NVH transmission.
The side-load compensated strut modules are designed to reduce the sliding friction caused by the bending load on the strut that is inherent in almost all suspension geometries. The side-load compensation geometry also allows the front wheels to be moved further outboard for improved stability. The configuration of the side-load compensated springs – visually these have an outward curvature – compensates for side forces within the shock absorbers cylinder that occur with conventionally shaped springs by ensuring optimised straight-line action for the damper.
Damping and spring rates have been tuned to achieve the best possible ride and handling characteristics depending on the powertrain fitted. Two distinct packages have been formulated to ensure the best ride and handling characteristics as adapted to the different powertrains and their impact on the overall weight of the vehicle.
The rear suspension system of the Sonic features a specially adapted compound crank (torsion beam) with a double walled, tubular v-shape beam profile. This design combines all the advantages of a conventional beam axle – such as minimised space requirements for installation – together with low weight and consistent camber control. This system can also be tuned to precise requirements, event to the extent of meeting specific regional market preferences.
Additional benefits include, like the front suspension, the ability to place the wheels for an enhanced rear stance together with a reduced space requirement over the traditional system. The reduced space requirement allows the fuel tank to be mounted between the wheels for lower positioning of the rear seats. Improved NVH attenuation is achieved through the use of larger bushes in the system. The ability to fully optimise the torsional or twisting characteristic provides for exceptional stability as well as agile handling.
A refined column mounted hydraulic power steering system is employed in tandem with a rack and pinion steering box.
The high precision design of the power steering system includes a wear compensator that features proprietary General Motors technology. The wear compensator continually adjusts the system interaction with the steering box to ensure precise steering action over the life of the vehicle without any play caused by normal wear becoming apparent.
The steering column can be adjusted for both reach and height to achieve a best-fit characteristic for the driver. Tilt adjustment covers a rake angle of plus or minus 2 degrees. Telescopic adjustment covers the range of 20mm in and 25mm out from the neutral position.
The braking system of the new Chevrolet Sonic has vented disc brakes at the front coupled with a drum brake system at the rear. Brake linings are of non-asbestos organic material with an enhanced wear life, reduced noise characteristic and excellent pedal feel. The parking brake is a cable operated mechanical system.
An ABS anti-lock system is standard on all models of the Sonic offered in South Africa. This is a four channel system that includes a panic brake BAS (Brake Assist System) that will automatically apply more brake pressure when and urgent stop pedal brake pedal motion is detected.
Front-to-rear proportioning of the braking effort is controlled by an integral ABS function – EBD – Electronic Brake Force Distribution. This makes use of independent control of the rear braking system for improved stability and braking during cornering as well as more effective use of the rear system when vehicle loading is increased.
Tyres are 195/65 R15 fitted to 15 inch alloy wheels to provide an effective contact patch with the road for the transmission of braking forces.