DETROIT - Some of the same technologies that make the 2012 Regal GS sport sedan the brand's top performance car contribute to the stability and comfort that defines Buick.
Buick's HiPer Strut system is an example of the best-of-both-worlds approach. Short for High Performance Strut, this piece of hardware creates a better separation between the front suspension's steering and shock-absorbing functions through added components that enable the steering knuckle to rotate independently from the strut tower. Ideal suspension geometry is maintained, reducing torque steer and improving camber control.
What that means to drivers is that torque steer - the sensation of the car pulling the steering wheel to one side - is virtually eliminated, steering response is improved, and overall control is better. It delivers some of the advantages of all-wheel drive, but without the added weight and complexity.
"HiPer Strut raises the limits of how a front-drive car can perform." said lead engineer Bill Rietow.
The stability allowed by HiPer Strut let engineers package an advanced four-cylinder turbocharged engine with the highest horsepower-per-liter ratio General Motors has ever produced. At 135 horsepower per liter, it is also the most power-dense engine ever certified by the Society of Automotive Engineers. The car's 270-horsepower rating wouldn't be possible without fuel-saving technologies like spark ignition direct injection (SIDI) and variable valve timing.
Computer controls that smooth engine performance and increase efficiency also allow predictable response to the driver's gas pedal inputs.
Buick Interactive Drive Control System, standard on the Regal GS, puts control over the balance of performance and comfort at the driver's fingertips. Through a set of "Sport" and "GS" buttons, drivers can alter suspension, steering, and gear shifting characteristics. "Sport" suspension is 20 percent stiffer than the base setting, while "GS" is 20 percent stiffer than "Sport." While the car is moving, the engine computer constantly analyzes road conditions - thousands of calculations each second - to fine-tune suspension characteristics.
Other driver controls in the Regal GS are tuned for a pleasant experience. With a six-speed automatic transmission, shifts are smooth and programmed to save fuel during normal driving. When in "GS" mode, the transmission shifts are firmer and quicker to sharpen performance.
Regal GS caters equally to manual transmission enthusiasts. While these drivers select their own shift points, they are aided by a Hill Start Assist feature that, when the car is stopped on an incline, automatically engages the brakes for a few seconds while the driver releases the clutch, preventing the jolt that comes when a car rolls back.
"I've been driving manuals my whole life, but I still find the security of Hill Start Assist reassuring," said Rietow.
The engine control module in the GS also briefly cuts fuel and reduces spark advance when the driver depresses the clutch, allowing to turbocharger to maintain boost for quick and smooth "no-lift" shifting at wide-open throttle.
"The Regal GS uses purposeful technology to create an intelligent brand of performance," said Rietow.
GS recently won a Car and Driver sport sedan comparison test against the 2012 Volvo S60 R-Design and was recognized on the Hagerty Insurance "Hot List" of future collectible cars.
Source: GM
