Development
Cadillac, upon discovering that the public wanted something small and designed with consideration, began full-scale development of a compact car from 2009; that car being given the designation "ATS".[11] The ATS was developed by GM engineers working principally at the General Motors Technical Center in Warren, Michigan, United States.[19] General Motors invested US$190 million to upgrade the Lansing Grand River Assembly plant for ATS production which created 600 jobs in the result of a second shift of workers.[20][21] GM began assembling vehicles intended for sale to customers on 26 July 2012.[22] In August 2009, vice president of design Edward Welburn revealed a full-size styling buck of the ATS alongside the XTS luxury saloon.[23]
To establish parameters around which they would design the ATS, GM engineers benchmarked the 1999-2006 BMW E46 3 Series, which ATS chief engineer Dave Masch and his team regarded as the most dynamic and driver-focused iteration of the 3 Series.[24] The engineers emphasized low weight when developing the ATS and their efforts resulted in a finished vehicle that weighs less than the BMW E46 benchmark.[11] To achieve this result, Masch suggested that the engineering team disregarded certain GM product development rules that, had they been followed, would have resulted in a heavier vehicle.[25]
During the early development of the ATS, GM engineers determined that downsizing the GM Sigma II platform that underpinned the second-generation CTS would make the car too heavy, and that using an economical, front-wheel drive platform would sacrifice performance expected of a Cadillac sedan. Under the leadership of Dave Leone, GM engineers created a brand-new platform which was designed to be light and compact, to be capable of handling both rear- and all-wheel drive configurations and to have a near 50/50 weight distribution. The new platform developed by the GM engineers for the ATS was called the GM Alpha platform.[26]
Cadillac took two years to conclude the development of the ATS. Ken Kelzer, engineering executive for GM,[27] said that it would have been possible to simply cut down a CTS, which would have resulted in what Kelzer calls a "pretty good car". However, he states that as the BMW 3 Series was its direct competitor, a unique platform would be optimal.[28] Larry Craig, the ATS Program Engineering Manager says that several iterations were completed until a compromise was made between manufacturability, weight and strength. Consequently, the lightest ATS weighs 3315 lb, compared to a BMW E46 328i at 3461 lb.[29] Dave Leone, vehicle line executive for rear-wheel-drive and performance cars, knew that downsizing the larger CTS would result in a small car not able to deliver the performance wanted in the segment. Leone states, that he and his team established a dollar-per-kilogram strategy to measure the cost-effectiveness of weight-reduction.[26] The engineers made sure to monitor materials used in developing the ATS; this resulted in an almost-perfect weight distribution figure of 51 percent and 49 percent for both front and rear, respectively.[30]
The exterior was designed by a team under the direction of Bob Boniface. Boniface says the well-designed exterior was due to its well-constructed interior and chassis, and so the design team desired to make its exterior as quality as its system. The design team worked closely with the engineering team to make sure its exterior design met all of the performance metrics they set out.[31] Taki Karras, ATS design manager, stated that it was significantly harder to make an entirely new architecture rather than reskinning something else.[31] Cadillac previewed a two-minute video, which featured an interview with General Motors North America President Mark Reuss, test-driving a pre-production development variant of the ATS, along with the ATS engineers and developers David Leone, Chris Berube, and Kevin Zelenka.[32]
Kelzer states that it took two years to develop kinematics models and building six mules to test theories, and additionally an extra three and a half years to go from formal program approval to production.[28] Tony Roma was the chief engineer of the ATS-V, which has 25 percent greater structural stiffness than a non-V ATS.[33] Cadillac debuted the production ATS to the press on 8 January 2012.[34] General Motors began selling the ATS in the United States in August 2012 as a 2013 model. Sales in China began on 21 November 2013.[35] Chinese-market vehicles were initially imported from the United States by Shanghai GM.[36] The Chinese-assembled ATS-L was launched in China in August 2014.[37]
Design
As is becoming increasingly more common, the ATS benefits from electric power steering, which was a rack-mounted, variable-assist and belt-driven system from ZF Friedrichshafen, internally known as the "ZF Lenksysteme".[38] Kelzer states that when GM was looking for suspension layouts, they were also looking at the various electric power steering systems available. Cheaper systems were available, but he states that it would have forced them to give up the premium feeling that the driver expects.[28] The ATS uses cast-iron for the rear differential, unusual for its class, as its competitors use aluminium housings. However, the heavier metal helps preserve the vehicle's 50:50 weight distribution, allows for improved fuel efficiency, among other benefits.[39][40] As cast iron has a lower thermal expansion rate than aluminium, the differential bearings have a lower pre-load. Noise is suppressed better, and the driveshafts are attached by bolts instead of splines, eliminating spline take-up and defeating noise, vibration, and harshness
