Not to be confused with Emperor (manufacturer)
In GTA San Andreas, the Emperor is based on an early-90's Infiniti Q45. IN GTA IV, it's based off of the 70's Cadillac Deville or Fleetwood.
GTA San Andreas
It is commonly found in San Fierro, and is used in Wear Flowers in Your Hair, the first mission in San Fierro where CJ hires Dwaine and Jethro to work in the garage in Doherty. It is also found in Grand Theft Auto IV.
Acceleration and speed are somewhat disappointing, as are handling and braking. The engine sounds as though it is a large V6 or V8, but is apparently incapable of delivering substantial power to the bulky, rear-drive vehicle. Using the E-brake around corners almost guarantees fishtailing. It is, however, a sturdy veichle, and does a fairly good job of absorbing damage.
GTA IV Rendition
Emperor In GTA IV, it is based on a 1977 Cadillac Deville or Fleetwood. It features a "beater" version of the Emperor, with junky paint finishes, broken seats and old wheels and tires.