The Nissan Altima is powered by either a 175-hp 2.5-liter I4 or a 270-hp 3.5-liter V6 and the transmission choices include a six-speed manual or continuously variable transmission (CVT). The trims on the Altima include: the 2.5 Base (on the sedan only), the 2.5 S, and the 3.5 SR. Safety features include: four-wheel disc brakes, anti-lock brakes, six airbags, active front head restraints, vehicle stability and traction control, front seat-belt pre-tensioners and a tire pressure monitoring system (TPMS). For a sportier appearance the coupe's roofline is 2.6 inches lower than the sedan's and flows back into a long and nicely sculpted tail section that narrows between wide shoulders above prominent wheel arches. The suspension is tuned to provide the driver with a more nimble feel and heightened responsiveness. For the 2010 model year, Altima receives a significant number of refinements, including a restyled grille, hood, front bumper and rear license plate finisher. Also, the 3.5 SE trim has been renamed the 3.5 SR.