Driving

On its launch in 2012, the original CX-5 set new dynamic standards, changing perceptions of how engaging a compact SUV could be. With its excellent body control, accurate steering and sharp handling the CX-5 was praised by media and customers alike.

Taking this strong base as the starting point, and with a chassis that has more than 50 per cent new components, the development of the second-generation Mazda CX-5 saw Mazda’s engineers work to deliver an SUV that takes the Jinba Ittai car-and-driver-as-one design and engineering philosophy to the next level.

The Mazda CX-5 sees Mazda’s latest Skyactiv-Vehicle Architecture concept, which was first introduced on the current Mazda3, applied to the CX-5, further evolving the bodyshell and suspension to provide both comfort and an engaging driving experience. Transmitted sounds and vibrations tend to leave a more favourable impression on human ears as the soundwave size and convergence time grow smaller or shorter. The same is true for ride comfort, so a damping control structure has been introduced to the bodyshell frame to reduce the wave size and convergence time of vibrations entering the cabin from the road surface.

In addition to strengthening the lateral rigidity of frame members near the centre of the body, structural adhesive was also employed for its vibration suppression qualities and its positive effect on vehicle manoeuvrability. When driving over uneven surfaces or bumps on city streets, cabin occupants must often use their hands and feet to maintain their seating position. This causes muscles to tense up, resulting in fatigue and even car sickness. To prevent this, the direction from which these forces enter the vehicle has been simplified. Increasing rigidity where the seat frames mount to the body limits input on the occupants to primarily a lengthwise direction. This reduces the unpleasant sensation and the load occupants are subjected to in such situations.

Other measures implemented to improve comfort and ride quality include changes to the damping characteristics of the suspension springs to help mitigate the degree to which occupants’ heads pitch forward and back when traversing bumps in the road. Maintaining a relaxing and supportive seating position is key to safe and comfortable driving for all cabin occupants. Informed by Mazda’s human-centred development philosophy, the CX-5 seat is designed to better stabilise head movement. To achieve this natural head movement when driving, the seats use their shape and the entire cushioned surface both keep the pelvis upright, and optimise the curvature of the spine. Maintaining the S-shaped curve of the spine allows it to respond flexibly to vibration transmitted from the pelvis and stabilise the head. In turn, this suppresses the amount and speed of both back-and-forth and side-to-side head movement, which serves to stabilise eye movement.

Working on handling stability, ride comfort and NVH (Noise, Vibration and Harshness) in unison, the CX-5 engineers’ development goal was to achieve a level of cabin quietness that would allow conversation amongst all occupants regardless of vehicle speed. Having set the ideal sound pressure, the engineers managed the resonance frequency of the suspension components to reduce road noise by separating it from cavity resonance within the cabin. This made it possible to greatly reduce the level of road noise, particularly when driving on rough surfaces such as gravel roads.

The responsiveness and controllability of the CX-5’s Skyactiv-Body and Skyactiv-Chassis ensure a feeling of complete command over the vehicle; all its movements are matching to the driver’s acceleration, steering and braking inputs as precisely as possible. Complemented by G-Vectoring Control (GVC), the Mazda CX-5 is more comfortable, refined and responsive than ever.

Underpinning this dynamic ability the CX-5’s Skyactiv-Body achieves high levels of performance in three key areas: collision safety, light body weight and rigidity. To strengthen the joints between the suspension components and bodyshell, 2mm thick apron gussets are adopted where the front suspension connects to the hinge pillars. The left- and right-hand side sill reinforcements adopt a closed cross-section, strengthening at the base of the A pillars is optimised and high-rigidity blown material is added to the cross-member brackets that join the rear of the side sills to both sides of the body.

Compared to the first generation model launched in 2012, bodyshell torsional rigidity is 15 per cent stiffer - this reduces the body’s response delay to steering inputs. Increasing the amount of ultra-high-tensile steel used by approximately 3 per cent over the first-generation model, helps realise significant gains in body strength. The A pillars feature 1,180 MPa ultra-high-tensile steel. The side sills and B pillars use 980 MPa ultra-high-tensile steel, enhancing safety performance and minimising weight increase. The use of hot-stamped 1,800 MPa steel - the world’s strongest - for the front and rear bumper reinforcements is a further safety feature.

Building on the rigidity of the CX-5’s shell, the steering, suspension and brake systems are all refined to enhance handling stability. To improve the response of the electric power steering system to driver inputs, the CX-5 adopts rigid couplings to provide a more direct connection between the steering system mountings and suspension cross-members.

Featuring proven MacPherson strut front and multi-link rear suspension systems, numerous fine-tuning measures have been implemented to further refine the Mazda CX-5’s chassis. The diameter of the front damper pistons is optimised to provide a more linear response and smoother vehicle behaviour when quickly turning the steering wheel. Optimising the damping characteristics and introducing more moderate behaviour above the springs also delivers smooth roll characteristics when entering corners, and a stable posture during cornering. In addition, the front lower suspension arms feature liquid-filled bushings, which increase the damping of minute vibrations.

Complementing this mechanical set-up is G-Vectoring Control (GVC): the first system from Mazda’s Skyactiv-Vehicle Dynamics range of technologies. Utilising integrated control of the engine, transmission and chassis to enhance the connection between car and driver, GVC varies engine torque to optimise the load on the front axle. By monitoring steering and throttle position when entering a corner under power, GVC momentarily reduces the amount of torque delivered to the front wheels, thereby transferring a fraction more weight onto the front axle. This increases front tyre grip, which allows the front wheels to turn more precisely.

Thereafter, when the driver maintains a constant steering angle, GVC immediately recovers engine drive torque, which transfers load to the rear wheels, enhancing vehicle stability. This series of load transfers extracts much more grip from both front and rear tyres, improving vehicle responsiveness and stability according to the driver’s intentions. The current CX-5 features the latest GVC Plus system, which offers even better yaw control at speed.

The indiscernible nature of GVC means that the driver subconsciously reduces any unnecessary steering and throttle movements through the corner. Even on a straight road, GVC can reduce driver fatigue and increase passenger comfort by removing the perceived need for the countless tiny corrections that some drivers make when driving straight. In doing this, GVC lowers driver effort and reduces the amount of head and body sway small steering corrections can create for passengers. Working to complement the mechanical grip of the CX-5, GVC is an unfelt companion that constantly helps the driver feel at one with the car – something that is at the very heart of Mazda’s Jinba Ittai driver-and–car-as-one ethos.

As good to drive as ever with improved refinement, the Mazda CX-5 retains its reputation as one of the most enjoyable driver’s cars you’ll find in the SUV segment.