The 2015 Nissan Altima is available in two main configurations: 2.5 or 3.5. The number signifies the engine specified (2.5-liter four-cylinder or 3.5-liter V6). From there, you'll have your choice of a base model (2.5 only) or increasing amounts of features through the S, SV and SL trim levels. Note that early in the model year, the 3.5 version loses its S and SV trims, leaving just the loaded "SL" trim level.
The base 2.5 Altima sedan starts with 16-inch steel wheels, full power accessories, a 4.3-inch LCD information display in the gauge cluster, a height-adjustable driver seat, Bluetooth phone and audio connectivity, and a four-speaker sound system with a CD player and an auxiliary input jack.
The 2.5 S steps up to automatic headlights, keyless ignition and entry, cruise control, a six-speaker sound system and an optional power driver seat with six-way adjustability (i.e., a powered version of the standard seat). It's also eligible for the Display Audio package, which contributes a 5-inch touchscreen display, a rearview camera, a USB port, satellite radio and smartphone app integration (NissanConnect).
The 2015 Nissan Altima comes standard with antilock brakes, stability and traction control, front side airbags and side curtain airbags. A rearview camera is optional on 2.5 S and standard on 3.5 S and all SV and SL models. Blind-spot monitoring, rear cross-traffic alert and lane-departure warning are available on the 2.5 SV and 2.5 SL and standard on the 3.5 SV and 3.5 SL.
In Edmunds testing, an Altima 2.5 SV sedan stopped from 60 mph in 123 feet, which is average in its segment. A 3.5 SL, however, stopped in a superb 114 feet -- about 10 feet shorter than the norm.
In government crash testing, the Altima sedan received a perfect five stars for overall crash protection, with five stars for total frontal impact safety and five stars for total side impact safety. The Insurance Institute for Highway Safety (IIHS) gave the Altima its top "Good" rating in its moderate-overlap frontal-offset, side-impact, roof-strength and whiplash reduction (seatbelts and head restraints) tests. In the small-overlap front-impact test, the Altima earned an "Acceptable" rating (second best).