The Mazda6 embodies Mazda’s radical SKYACTIV chassis and body technology philosophy. Its chassis, steering, suspension and brakes have been designed and developed to deliver an excellent combination of dynamism and cosseting ride comfort, while lightweight construction technology significantly enhances fuel economy, refinement levels and safety standards.
Key to this exceptional skill set is the Mazda6’s lightweight and rigid chassis structure. To achieve the seemingly incompatible goals of developing a chassis that was both lighter and stiffer, Mazda’s engineers developed an advanced straight and continuous body framework, in which each body section functions in a coordinated manner with those around it. This eliminated the concentration of energy at any given point by facilitating its distribution throughout the structure in a front, side or rear impact.
Curves were removed as much as possible form the underbody structure to create this desired straight frame in a continuous configuration from nose to tail – an engineering approach first employed in the Mazda CX-5, and more recently in the Mazda3.
For those sections of the frame that still required some curvature, engineers implemented continuous bonding with the horizontal frame to make the structure a closed section, contributing significantly to weight reduction while simultaneously boosting rigidity.
The result is a three-way impact absorption system: an upper path through to the A-pillar, a middle path through the flanks of the chassis and a lower path through the underbody. The programme engineers were also able to achieve an ideal 50:50 weight balance for the Mazda6, further enhancing its balance and stability.
This far-reaching design called for advanced production techniques and a significant increase in the use of high-tensile steel. The SKYACTIV-Body of the Mazda6 uses 20 per cent more of this robust and impact-resistant steel than the previous model.
The Mazda6 is also unique in its sector with its use of 1,800Mpa ultra-high tensile steel, and this incredibly strong form of steel is employed in the front and rear bumper beams – the first line of defence in the event of most collisions.
The innovative body layout called for some equally inspirational new production methods, including weld bonding for the roof-rail section and wheel wells to create a reinforcing structure, and enables parts to be attached to this section in advance and sent to assembly line as a single unit.
Mazda also bonded the upper body vertical ring structures to a reinforced section of the underbody, significantly increased the number of spot welds throughout the construction and employed a dual brace to bond the rear suspension mounting positions to the chassis.
The resulting lightweight and ultra-stiff construction was also hugely beneficial in the suppression of Noise, Vibration and Harshness (NVH), where load and engine noise were separated and dealt with independently. In the upgraded model, additional sound-deadening material has been added to the headliner, the floor and sides of the boot, and around the dashboard. Together with improved door seals, larger side sills and additional underbody sealing, in-cabin NVH levels have been improved during motorway driving.