There are six varieties of Sentra, four of which are powered by a 2.0-liter 4-cylinder engine making 140 hp and 147 lb-ft of torque. These four 2.0 models ? 2.0, S, SR and SL -- have a CVT standard, with a 6-speed manual available on the base 2.0 model only. The other two models, the SE-R and SE-R Spec V, have a 2.5-liter 4-cylinder engine. The SE-R produces 177 hp and 172 lb-ft of torque, and is mated to a CVT. The SE-R Spec V has been tweaked to make 200 hp and 180 lb-ft of torque. It comes with a 6-speed manual transmission and a specially tuned sportier suspension. All Sentra engines have direct injection and a drive-by-wire electric throttle. Electronic brake force distribution and ABS are standard on all but the base 2.0 model, where they are available as part of an options package. Speed-sensitive steering is standard on all versions, as is Nissan's Advanced Air Bag System, steel side-door guard beams and a tire pressure monitoring system. Beyond the engines and safety systems, the six Sentras start to diverge. The 2.0 starts with some nice basics for the price, like power windows and doors, air conditioning, and 60/40 split rear seats. The 2.0S adds a trip computer, cruise control and a 6-way adjustable seat. The 2.0SR spruces up the exterior with 16-inch, 7-spoke aluminum alloy wheels, fog lights, a rear spoiler and a sport grille. The 2.0SL gets Bluetooth and the Nissan Intelligent Key keyless entry and ignition system. It also has interior upgrades like a leather-wrapped steering wheel and wood-tone trim. Several optional packages are exclusively available for this trim, such as the Leather Package. The Premium Package adds a moonroof; the Premium Plus Package adds a moonroof and heated front seats. The Tech Package swaps in a Rockford Fosgate 8-speaker audio system and a rear-view monitor. The SE-R gets bigger brakes for more stopping power as well as sport-tuned springs and a rear spoiler. The SE-R Spec V gets even bigger brakes -- 12.6-inches versus the SE-R's 11.7-inch -- and a 25mm front stabilizer bar. The sport-tuned suspension gives the Spec V a lower ride, with shocks and struts set for stiffer handling. The SE-R Upgrade Package adds the keyless entry and ignition system, moonroof, upgraded stereo and rearview monitor. A similar package for the SE-R Spec V adds a limited-slip differential, but doesn't include the Intelligent Key system.