The 2008 Mercury Grand Marquis is about as far from a performance sedan as sedans get, but at least its engine offers decent performance and the overall ride is comfortable.
For 2008, Edmunds writes that "only one engine and transmission are offered on the Grand Marquis: a 4.6-liter V8 coupled to a four-speed automatic that sends 224 horsepower and 275 pound-feet of torque to the rear wheels." The V-8 engine scores fairly well in reviews read by TheCarConnection.com, though ConsumerGuide feels that it offers "lazy merging and passing response in a broad 40-60-mph range." They do, however, applaud the engine on the Mercury Grand Marquis for being "generally smooth and strong around town." Kelley Blue Book reviewers agree, praising the "velvet-smooth V8" for providing "excellent pulling power in the form of strong low-end torque, making it terrific for easy, effortless driving."
The four-speed automatic in the 2008 Mercury Grand Marquis doesn't hold up quite so well with reviewers. ConsumerGuide testers say that "the transmission's tardy downshifts" are responsible for much of the poor mid-speed performance of the engine. In most driving, however, Kelley Blue Book claims that the "four-speed automatic transmission delivers smooth, quick shifts." One point Motor Trend brings up that is worth mentioning is that "several of the Grand Marquis's peers have five-speed automatics available."
Fuel economy in the 2008 Mercury Grand Marquis is pretty much average for the class. ConsumerGuide testers "averaged 17 mpg" and rated the 2008 Mercury Grand Marquis a 4 out of 10 for fuel economy, versus a class average of 4.2. The EPA estimates for the 2008 Mercury Grand Marquis are 15 mpg city and 23 mpg highway, but Kelley Blue Book says that "many owners actually report beating the EPA highway number on interstate-type highway cruising, as once the Grand Marquis gets up to speed and into overdrive it's working very easily."
Although the Mercury Grand Marquis might get up to speed with relative ease, its handling is downright awful. Edmunds says "due to the vehicle's size, pillow-like suspension and low-effort steering, it has all the road feel of a two-mast schooner." ConsumerGuide agrees, citing the Mercury Grand Marquis for "marked body lean and mediocre tire grip in fast cornering." Ride quality, however, benefits greatly from the soft suspension, and Motor Trend says that "cushiness" is "where the Grand Marquis excels; bumps don't jolt the cabin, they merely exacerbate the floating undulations." They also add that "braking performance is acceptable but hardly great, and the pedal feels as mushy as the rest of the controls."