Cadillac knew that a lightweight chassis was essential if they wanted to create the kind of car that would handle and drive like a world-class sports sedan. A lightweight structure not only benefits handling, but improves acceleration and fuel economy as well. The ATS weighs in at around 3,400 pounds, which is extremely light among luxury cars. This helps it achieve an EPA estimated 33 mpg on the highway when properly equipped. Engine choices available on the ATS sedan take advantage of its light weight to provide strong fuel economy and acceleration. Three engines are available, a base 2.5L 4-cylinder rated at 202 horsepower, a 2.0L 4-cylinder turbo making 272 horsepower and 295 foot-pounds of torque, and a 3.6L V6 producing 321 horsepower. All three engines come with a 6-speed automatic, though a 6-speed manual is available with the turbo engine. All-wheel drive is optional, and it is only available with the turbo engine or the V6. The ATS coupe is not available with the 2.5L. In either sedan or coupe form, the ATS comes in four different trims: Standard, Luxury, Performance and Premium. In each trim, sedans and coupes are comparably equipped, with subtle differences. Standard sedans come equipped with either of the 4-cylinder engines, for example, while coupes feature only the turbo. The base stereo in the sedan is a 7-speaker Bose surround sound unit, while the coupe features a 9-speaker Bose unit. Sedans include Sirius satellite radio and Bluetooth connectivity, while Standard coupes lack Bluetooth. Other notable standard equipment includes a leather wrapped steering wheel with audio controls, a 6-way power adjustable driver's seat, a 4.2-inch color information display, dual-zone climate control, and attractive 17-inch wheels (18-inch on the coupe). The Luxury trim adds leather seating surfaces, 8-way power adjustable front seats, power mirrors, front and rear ultrasonic parking assist and Cadillac's CUE information system. CUE relays information to the driver using an 8-inch touch screen located in the center console. Functioning much like an iPad, CUE vastly simplifies the interior of the car, allowing for increased functionality without much of the clutter. It also houses the optional navigation system. Performance-equipped ATS models include just about everything in the Luxury package, but add a 10-speaker stereo (12 in the coupe), aluminum pedals, HID headlamps, automatic wipers and sportier front seats. The Performance trim is only available with turbocharged or a V6-engined ATS. Top-of-the-line Premium trim is likewise only available with the two more powerful engines. It includes a full color programmable heads up display, 18-inch wheels and Magnetic Ride Control shocks, which can instantly adjust suspension stiffness as the car moves over the road, providing both a sublime ride and amazing handling. Standard safety equipment on the ATS includes anti-lock brakes, traction control, stability control, OnStar crash response and front, knee and side-curtain airbags.