When Mazda introduced the Mazda6 in 2003, it was the result of the brand's plan to build a global C/D segment sedan that could attract the attention of buyers in Europe, Asia and North America with little product differentiation. Mazda's approach was much different than those taken by Toyota, Honda and Nissan, all of which had developed midsize sedans specifically tailored to U.S. buyers, complete with larger cabins and bigger engines than those offered in the rest of the world. Mazda miscalculated: sales of the 6 never surpassed the 72,500 unit mark-available annual production capacity at the Auto Alliance plant in Flat Rock, MI, (where the 6 is built alongside the Ford Mustang) is 120,000 units for the 6-and it lagged far behind the competition in overall quality (ranking as low as 14th in the segment in the J.D. Power Initial Quality Study). "There were areas where the current Mazda6 did not meet the expectations of the U.S. market-quality, power and size," says Tim Barnes, director of product strategy and planning for Mazda North America, who points out most of the quality problems centered around attribute issues: ease of use of navigation systems, Bluetooth integration, HVAC controls, and the like. The problems that plagued the Mazda6 could have been avoided if Mazda's parent, Ford, would have followed their original plan, which called for developing a joint C/D vehicle in Cologne, Germany, with specific North American variants. That program was killed and Mazda was left with a single sedan throughout the world.
Not wanting to repeat the foibles of the past, Mazda engineers and designers worked to address the shortfalls of the current generation Mazda6 by developing a version that's tailored specifically to the North American market (read: bigger, more powerful and equipped with less complicated electronics). For starters, there's the size: the new 6's wheelbase is 4.5 in. longer than its predecessor (109.8 in.), and the overall length has been increased by 6.9 in. to 193.7 in. Vehicle width has also increased 2.3 in. to 72.4 in. In order to accommodate these new dimensions, the base CD3 architecture (the same backbone used for the Ford Fusion, Mercury Milan, and Lincoln MKZ) has been modified to accommodate the changes. "The firewall is the same as the current car, and if you look at the car from a base architecture and backbone engineering standpoint, we've carried over about 70% of the architecture. However, if you look at it from a body-in-white perspective, this is what we call a 'CD3-plus,' because it has been stretched, lengthened and is reinforced differently," Barnes says.
With a focus toward improved vehicle rigidity, engineers utilized Mazda's Triple H architecture design, which includes a robust rocker connected to the B-pillar through the upper roof panel. The number of spot welds has increased and weld bonding adhesives have been added for improved stiffness (Mazda says weld bonding provides a 20% improvement in rigidity over traditional spot welding) and the application of high-strength steel (MPa 590-780 has been used in the center structure) has increased 30% over the previous model. The result: bending rigidity is 39% higher, torsional rigidity is improved by 17% and flexing in the rear package shelf has been reduced by 29%.
Mazda had another goal for the 6: Establish Mazda's new design theme: bold, cool and exotic. Designers at all four design studios (Hiroshima, Yokohama, Frankfurt and Irvine) competed for the exterior design prize, but in the end two designs were put against each other to battle it out in focus groups. "One was more youth-oriented and coupey, while the other was more elegant. In the end we chose the more sophisticated front end of the elegant one, along with the more pronounced wheel arches of the youthful model," says Franz von Holzhausen, design director for Mazda North America. The fenders, which Mazda designers had to battle to keep, are the signature cue of the 6, according to von Holzhausen: "Any Mazda expresses this idea of a fuselage with wings attached and that's what the fenders do." The battle developed as a result of the added steps needed to stamp the fenders (the depth of draw is beyond standard limits and requires three stage stamping dies), which added cost. "They told us it was going to be ridiculously expensive and we thought it was one of those elements that conveys precision and it was important for us to show the quality; we were adamant about it," von Holzhausen adds.
Making the larger body seem smaller was another task design tackled through the use of a wide, lower grille; a long feature line flows from the front fascia into the rear clip to help visually reduce the size. Designers also paid special attention to elimination of unnecessary shut lines on the front end by incorporating the hood shut line into the front fender edge. "The shut line is right on the feature line, which takes an extra visual line out of the appearance of the car and makes it look cleaner. We in design worked together with the engineers in Hiroshima to come up with this," von Holzhausen says.
A driver-oriented cockpit is a given for Mazda, but careful attention has been paid to materials and gloss levels. For the optional leather interior, the design team chose to use the leather found in the CX-9 crossover, while soft touch trim is used throughout the cabin with chrome accents placed on all the touch points to improve switchgear feel.
Mazda also focused on its Auto Alliance plant as a key part of the equation to improve the overall quality of the 6 both from a perception and build standpoint. "A lot of attention was put into this car as far as manufacturability is concerned. There's a tremendous amount of lessons learned from the current Mazda6 that we have experienced in terms of some quality issues from a perception standpoint in terms of gaps and margins, fit-and-finish, squeak and rattle and all of that comes down to tolerances, which we reduced on the whole exterior by 50%," says Barnes. The placement of the manufacturing stations was also modified for the new 6, while the number of modules has also increased to reduce potential defects. To tackle the issues surrounding electronics reliability and usage, Mazda added an end-of-line testing station that uses a diagnostic plug to verify all electronic modules are working properly and communicating with one another. If an issue is detected, it is fed into the plant's database where engineers are alerted to investigate potential problems.
A focus on improved quality and reliability provided an ideal opportunity for Mazda's engineering team to investigate ways to leverage parent Ford's parts bin for proven components and systems that can be shared with the new Mazda6. The front seat frames, for example, are shared with the Ford Mustang (foam density and layout are unique to Mazda6), while the HVAC system; throttle bodies and fasteners are also borrowed from the Ford bin. Ford also designed the optional 3.7-liter MZI V6-minus the electronic throttle calibration-which is also used in the CX-9, Lincoln MKS and 2010 Ford F-150 pickup.