It is rear-wheel drive, giving it some good traction and strength, however due its longer length than the Rancher and the Police Ranger gives it a somewhat "slower effect" and it has the tendency to flip in uneven terrain, so it is not suitable for off-roading, but it is modified for on-road high-speed chases, although strangely it is outfitted with off-road tires in San Andreas. It is faster than a police car, and is capable to catch even the fastest cars of the game. Due to its weight, it can even flip totally your car during a chase. This is helpful in vigilante missions because it can stop the cars more easily than a police car. An advantage to it is that a blue beacon and siren and driving on a road full of cars will make them split and free the road for the player. It resembles an early 90's Chevrolet Suburban.
Just like the real life Chevy Suburban, the FBI Rancher has a throaty V8.
The FBI also use the FBI Washington in Vice City.
[*]You can change the black paint of the FBI Rancher by using a pay'n'spray/mod garage hack or a trainer capable of changing car colors.