The 2007 Nissan Altima is part of the fourth generation. It offers 2.5 S, 3.5 SE and 3.5 SL trims, powered by either a 2.5-litre four-cylinder engine with 175 horsepower or a 3.5-litre V6 engine that offers 270 horsepower. Both engines come paired with a six-speed manual standard transmission, and a continuously variable automatic transmission (CVT) is optional. Moreover, the Altima's continuously variable transmission (CVT) was a first in the midsize sedan segment. It features an easy-to-use control layout and innovative ‘Intelligent Key’ ignition system. The Altima also offers a satisfactory bare-bone CD stereo system while upgrades included a nine-speaker Bose unit, satellite radio and a rearview camera. Standard safety equipment includes front-seat side airbags and full-length side curtain-type airbags, also anti-lock brakes are standard on all but the 2.5 base model.