Buick essentially matched the output of a 3.5L V6 with a turbocharged 4-cylinder engine. Power delivery is mostly linear, but there is some elastic turbo-lag at low rpm. Fuel economy will suffer greatly if driven hard--27 hwy mpg is achievable.
Driving Dynamics
Undoubtedly, the chassis is the most rewarding part of this car. Extensive engineering went into suspension/steering design. Combined with the summer tires, the Regal GS can hold its ground with the best sport sedans.
Ride Comfort
Driver-selectable 3-mode suspension is standard, however, the differences are somewhat subtle. That said, the ride is always composed--more so than many other sport sedans. We'd call it firm, but never harsh; sophisticated not busy.
Quietness
You might hear an occasional turbo whine/whoosh (especially with the windows down--and that may be by design), but the Regal GS generally offers good wind and road noise isolation.
Ergonomics
Since its introduction, the Regal's center stack has been the target of criticism: Button placement seems random and functionality is not intuitive. Most other cockpit controls and levers work quite well and the driving position will suit many.
Visibility
Visibility is challenging: thick A-pillars and large mirrors to the front, high beltline, thick C-pillars, and a sloping roof line to the small, rear window. Parking sensors are standard front and rear; reverse camera is not available.
Seat Access & Space
The Regal is on the small end of the Midsize segment. GS-specific front seats are fantastic and measurements are comparable to those of another midsizer (VW Passat), however, rear passengers will find about 2-in less room in every direction.
Cargo & Storage
At 14.2 cu-ft, the Regal's trunk is generous and well-finished with shrouded hinges and fold-down rear seat backs.
Build Quality
Standard, upgraded materials adorn the top-tier Regal's interior. Build quality inside and out appears to be competitive but not benchmark in any way.