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 3400 lbs., which is extremely light among luxury cars. This helps it achieve an EPA estimate of up to 33 mpg on the highway when properly equipped. Engine choices available on the ATS 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 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 adds about $2,000 to the price of the car and it is only available with the turbo engine or the V6. The ATS comes in four different trims. Standard, Luxury, Performance and Premium. Standard cars come equipped with either of the 4-cylinder engines and plenty of standard equipment. The base stereo is a 7-speaker Bose surround sound unit with dual USB ports, Sirius satellite radio, Bluetooth connectivity, an auxiliary input port and an SD card reader. Other notable standard equipment include 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. The Luxury trim adds premium 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, 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 use small pieces of metal in the shock absorbers in conjunction with electromagnets to 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.