It may not set your pulse racing the same way an MX-5 does, but Mazda’s CX-5 is an important vehicle for the car company. Like it or not, the crossover is king in the US. Buyers simply prefer SUVs and CUVs over hatchbacks, sedans, and station wagons, and Mazda’s sales for the CX-5 reflect that. In fact, it’s the second-quickest Mazda to sell more than 1 million units—after the aforementioned MX-5.
Mazda says that the CX-5 accounts for a quarter of its total sales these days and moved more than 370,000 of them in 2016 alone. So the car maker has a lot staked on the new model, particularly since—as we learned during the briefings that preceded being given the keys—its shifting its sights further upmarket than one might expect. According to its data, the average Mazda customer today has a significantly higher income than even five years ago ($80,000 in 2011 vs. $93,000 in 2016). So Mazda has decided to embrace that demographic and accept that it can’t compete with the likes of Toyota or Honda on volume.
In a brave move—one wonders at the corporate discussions that must have taken place—Mazda even brought along a handful of crossovers from other companies for journalists to compare with the CX-5 models. These are the same rival crossovers that Mazda benchmarked during development. The choice of competition reflected the company’s upmarket aspirations: an Audi Q3, BMW X1, Lexus NX, and Mercedes-Benz GLA. Even the cheapest of these rides is still almost $9,000 more than the $33,465 (with options) CX-5 Grand Touring all-wheel drive vehicle we drove. (The CX-5 range starts at $24,045 for a front-wheel drive CX-5 Sport trim.)
Despite the new CX-5’s superficial similarities to the first generation, the 2017 model is much improved. Even though the body panels are all new, they still keep the design philosophy that Mazda calls Kodo (and which it showed off to beautiful effect on its RT24-P endurance racer). But the changes are more than skin-deep, and they mainly focus on several key areas: improving NVH (noise, vibration, and harshness) and ride quality without sacrificing handling. The new CX-5 also improves throttle response and linearity.
So much detail work
Dave Coleman is Mazda’s manager for vehicle dynamics and engineering. He gave us a fascinating (if you’re a car nerd like me) overview of the tons and tons of detail work that went into the new CX-5. Take NVH levels: Coleman’s team managed a 10-percent decrease in high-frequency noise and a 1dB reduction in low-frequency noise (as measured from the driver’s seat). But how, specifically, did Coleman and his team do that?
To start with, they moved the windshield wipers to below the hood line and, therefore, out of the airflow when driving. To better maintain sealing pressure at speed, an extra seal was added to the two existing seals between the front and rear doors. Plenty of new seals were added to the windows, the rear hatch, and so on. The front windows now use acoustic glass, which sandwiches sound-dampening vinyl in between the inner and outer glass. The windshield is slightly thicker. The A pillar was re-profiled to reduce turbulence. Panel gaps were made tighter, and a felt-lined plastic undercover underneath the vehicle now absorbs road noise.
Surfaces that could reflect sound in the cargo area were changed to absorptive materials, and sound paths from the vehicle’s floorpan were blocked. Now air is channeled through a special sound path on its way out of the car. The natural frequency of the front strut suspension was lowered, as was the natural frequency of the rear subframe, both through the addition of dynamic dampers (think a weight that’s placed and tuned to cancel out certain vibrations). The car’s headliner was changed to be less reflective of noise, and insulation has been increased behind the doors panels and in the C and D pillars. Mazda added carpet to bits you can’t see, like underneath the center console, all in the aid of a less tiring cabin.
Ride vs. handling
Improving ride quality without compromising the steering was similarly involved, according to Coleman. The steering rack is now solid-mounted to the chassis. The front suspension struts are lower-friction, and the perch angle of the front springs—now asymmetric—was moved to more accurately cancel out side loads on the strut. Mazda also uses what it calls “G Vectoring Control” to benefit ride quality. This works by reducing engine torque by tiny amounts—1-2lb-ft at most—when it detects a steering input. As the torque decreases, weight transfers toward the front axle, increasing the load on the front tires and stiffening the tire carcass as a result. It’s almost imperceptible, but the result is less body roll on initial turn in, which means a smoother ride for the passengers.
Mazda wanted a more direct throttle response for the 2.5L four-cylinder engine. But, unlike most of its peers, the company eschewed forced induction, although the engine does have direct injection. According to Coleman, in high-compression engines like the CX-5’s, knock (premature ignition of the fuel-air mixture) is the real killer both for peak power output and transient throttle response. Mazda found that the edge of the engine’s pistons turned into hot spots that could potentially trigger knocking, and so the piston edge was cut away to prevent this.
Other engine changes included asymmetric oil rings so that they better clean oil from the cylinder wall on the downstroke and better apply a film of oil on the upstroke. The piston skirts were also changed to asymmetrical ones. Why? Because, due to the different angle of the conrod, the compression forces on the piston head work in opposite directions during combustion and compression strokes. Those tweaks had almost no effect on overall power—187hp (139kW) at 6,000 rpm compared to 184hp (137kW) at 5,700rpm. But the response time of the engine to a throttle input was much better in real-world driving conditions.
We also got another fascinating—to me at least—presentation from Dave Coleman that delved into biophysics and the intriguingly named “minimum jerk theory.” This theory mainly involves the time lag between an input and movement and at what point that crosses a threshold and becomes noticeable. (This is around 250ms; any longer and we detect lag). To put all that in plain English, in this context, we’re talking about things like decreasing the time between pressing the accelerator or brake pedal and feeling a response.
The above is particularly important to Mazda’s “Jinba Ittai” philosophy, in which horse and rider—or in this case car and driver—work in harmony. Too much lag between an input and the car reacting means the driver ends up feeling like they’re on a ride rather than in control, Coleman told us.
Listing image by Mazda