The Xterra is available in four trim levels: X, S, Off-Road, and SE, each offered with 2WD or 4WD. All are powered by the 4.0-liter V6. The standard transmission is a six-speed manual; a five-speed automatic is optional on most models but standard on the SE. The entry-level Xterra X is a basic model with wind-up windows. It is also available with an automatic. Safety equipment for all Xterras includes an advanced air bag system, which consists of dual-stage front supplemental air bags with seat belt sensors and a front occupant classification sensor. Also standard are three-point seat belts for all rear seat occupants (including the center-rear position) and a child seat anchor system.For 2006, a new base model has been added that drops the price of entry by nearly a grand.