GM offers the 2012 Buick Regal with three different engines: a 2.4L 4-cylinder eAssist engine on the base Regal, a 220-hp, 2.0L 4-cylinder on the sporty Turbo model and a 270-hp 2.0L on the performance-minded GS. The base models are hooked up to a 6-speed automatic transmission in this front-wheel-drive sedan, while the Turbo and GS models are available with either a 6-speed automatic or 6-speed manual. The turbocharged engine in the GS is intended to perform like a V6, producing low-rev torque that's comparable thanks to a quick-response twin-scroll turbocharger. Estimated fuel economy figures for the eAssist engine are be 25 mpg city, 36 highway, while the turbo produces 18 mpg city and 27 mpg highway. The eAssist model is a light hybrid, with an electrical system intended to boost power and save fuel. In this case, the battery pack and electric motor are good for 15 horsepower and 79 lb-ft of torque on demand. The energy isn't stored like in typical hybrids. Rather, it's constantly generated, thanks to regenerative braking, and used as needed. The system works quite well--drivers who don't already know about the system won't even notice it working. On the outside, the Regal has a curvy, aggressive and performance-oriented look, and that carries over to the inside, where the Regal includes firmly bolstered sport seats and has an instrument panel that flows uninterrupted through to the door panels. Ice-blue lighting and a thick-rim steering wheel set a sportier mood than that of Buicks of the recent past. Among the safety features included with all Regal models are electronic stability control, anti-lock brakes and a full roster of airbags (rear-seat thorax bags will be available); the Regal's stiffer, more rigid body structure is a safety asset while helping with ride and handling. The Regal follows the same layout as the European-market Opel Insignia and its suspension (MacPherson struts in front, 4-link independent in back) was developed in Germany; it has been tuned for responsive handling while allowing a reasonably absorbent, though quite firm, ride. Hydraulic rack-and-pinion steering provides the right level of assist for high-performance driving, while 4-wheel disc brakes back it up with strong stopping power. One of the breakthrough features available on the Regal GS is the Interactive Drive Control System (IDCS), which integrates the stability control system with electronically controlled dampers, to allow a soft, comfortable ride when cruising but tighten up the suspension within milliseconds when needed for emergency maneuvers. The system comes with three modes: Normal, Tour and Sport, with the latter sustaining the sharper setting. Standard features on the Regal are generous, including a power driver's seat, heated front seats, leather upholstery, a Bluetooth hands-free system, XM satellite radio and the OnStar security and assistance system. Top options on the Regal include a navigation system and a Harman Kardon sound system with hard-drive storage for up to 10 GB for music, along with a USB port. GS models will include a host of extra appearance and performance features, including larger 19-inch wheels packaged with the IDCS system.