Essentially a carry-over from the previous year, the 2008 Mercury Grand Marquis is a six-passenger, rear-wheel-drive sedan availabe in entry-level GS and better-equipped LS models. Power for both models is provided by a 4.6-liter V8 engine that produces 224 horsepower. The flexible-fuel engine can be configured for either gas or E85 ethanol fuel. A four-speed automatic transmission is standard.

The 2008 Grand Marquis is equipped with a wide range of standard features, including four-wheel anti-lock brakes, a fail-safe engine cooling system, side-intrusion door beams, a tire pressure monitoring system, a SecuriLock anti-theft ignition system, and a Personal Safety System for the driver and passenger that includes dual-stage front airbags and safety belt energy management retractors.

Other standard features include air conditioning, power windows, mirrors, and door locks, an eight-way power-adjustable driver's seat, a tilt steering wheel with cruise control, 16-inch wheels with chromed covers, and an AM/FM stereo system with a CD player.