Unlike some midsize sedans, the Altima can have either four-cylinder or V6 power.Five trim levels are offered: base, S, SV, sporty SR, and top-shelf SL.Each comes standard with a 2.5-liter four-cylinder engine, making 179 horsepower.Fuel economy on the highway is rated by EPA at an impressive 39 mpg.

Only Altima SR and Altima SL sedans offer the 3.5-liter V6, which develops 270 horsepower and 251 pound-feet of torque.

Both engines mate with a continuously variable transmission (CVT), which is tuned for peak efficiency.With V6 power, the CVT can provide virtual gear ratios, mimicking a conventional automatic.

Not much is included with the base sedan, but the S model adds a proximity key and a 5-inch color LCD screen for the audio system.Altima SR features upgraded suspension tuning and bigger alloy wheels, suggesting a modest revival of the sporty nature that marked early Altimas.SV, the mainstream model, adds blind-spot monitoring and remote engine start.Leather upholstery and Bose speakers are among the premium extras in SL trim level.

All Altimas have a 4-inch LCD information screen ahead of the driver, as well as Bluetooth audio streaming.Nissan's navigation system, available for SV and SL versions, gets a 7-inch video screen and a selection of smartphone apps.

Named a Top Safety Pick+ by the Insurance Institute for Highway Safety, the Altima earned five stars from the National Highway Traffic Safety Administration for its frontal and side-impact crash testing.A four-star rating was given for rollover resistance (a calculated figure).

Availability of advanced safety technology isn't quite as impressive.Only the SL edition can be equipped with forward-collision warning that includes automatic emergency braking, for instance, and it comes in a costly option group.With the optional Tech Package, the Altima earned a Superior score from IIHS for frontal crash protection.

Still, Nissan offers a number of safety items, including blind-spot monitoring, rear cross-traffic alert, and adaptive cruise control.A rearview camera is standard on all but the base model.

Altima 2.5 SR ($24,470), the sporty trim level, includes special suspension tuning, 18-inch alloy wheels, and a power driver's seat.Design upgrades give the SR a somewhat distinctive appearance.Altima 3.5 SR ($27,990) is equipped similar to 2.5 SR, but with the V6 and LED headlights.

Altima 2.5 SV ($25,460) adds to S-model equipment such features as a power driver's seat, 17-inch alloy wheels, blind-spot monitoring, and rear cross-traffic alert.

Altima 2.5 SL ($28,570) features leather seat trim, a power passenger's seat, 18-inch alloy wheels, and Bose speakers.Adaptive cruise control, automatic braking, and navigation come in a Technology Package.Altima 3.5 SL ($32,690) is similar to 2.5 SL, but with V6 engine.

For plenty of midsize-sedan buyers, of course, that's not a drawback at all.While exhibiting a pattern of external bulges, the Altima is nevertheless cleanly designed.The sporty SR trim level derives a somewhat different look from smoked headlight housings, a decklid spoiler, foglamps, and distinctly styled wheels.

Optional leather upholstery on upper trim levels adds an appealing luxury factor.Still, the interior fails to come across as upscale or stimulating.

Impressively spacious overall, the Altima provides ample room in the back seat, thanks in part to the relatively long wheelbase.Dimensionally, though, rear legroom ranks around average for the midsize class, and passenger feet might not slide easily beneath the front seats.Most heads won't contact the headliner.

Comfortable Zero Gravity front seats, initially designed in accord with recommendations by NASA, offer plenty of head and leg space, even for a taller driver.Knee space is a tad limited by the dashboard.Acoustic glass and ample sound-deadening help keep the sedan pleasantly quiet.Measuring 15.4 cubic feet, trunk space ranks close to average.

Driving impressions by Andrew Ganz, The Car Connection.James M.Flammang contributed to this report.

Even in SR trim; an Altima cannot accurately be called sporty or particularly stimulating.Still, the SR, turbocharged or not, differs markedly from other Altima models.Stabilizers bars are thicker on the SR, and dampers stiffer.The suspension provides a welcome balance between passenger comfort and firm handling, without turning stiff.Other versions can yield a sense of floatiness when rolling through rough pavement.

Electro-hydraulic power steering tends to be slow, with excessive slack, though sufficiently precise.Brakes are effective, with good pedal feel.

The four-cylinder engine is wholly adequate and impressively thrifty.Acceleration is swifter with the V6, but that engine can sound a bit hoarse at lower speeds.On the highway, it's louder than expected in a sedan that's known for sedate travel.

Nissan has been a leader in CVTs, and the Altima version is impressively smooth as well as responsive.Using the virtual gear ratios in V6 and 2.5 SR models can reduce the tendency of the engine to run at high rpm, which otherwise yields a droning sensation.

Nissan's frugal four-cylinder powertrain is EPA-rated at 27/39 mpg City/Highway, or 31 mpg Combined.The SR drops to 26/37/30 mpg.A V6 Altima is EPA-rated at 22/32 mpg City/Highway, or 26 mpg Combined.

Unlike some midsize sedans, the Altima can have either four-cylinder or V6 power.Five trim levels are offered: base, S, SV, sporty SR, and top-shelf SL.Each comes standard with a 2.5-liter four-cylinder engine, making 179 horsepower.Fuel economy on the highway is rated by EPA at an impressive 39 mpg.

Only Altima SR and Altima SL sedans offer the 3.5-liter V6, which develops 270 horsepower and 251 pound-feet of torque.

Both engines mate with a continuously variable transmission (CVT), which is tuned for peak efficiency.With V6 power, the CVT can provide virtual gear ratios, mimicking a conventional automatic.

Not much is included with the base sedan, but the S model adds a proximity key and a 5-inch color LCD screen for the audio system.Altima SR features upgraded suspension tuning and bigger alloy wheels, suggesting a modest revival of the sporty nature that marked early Altimas.SV, the mainstream model, adds blind-spot monitoring and remote engine start.Leather upholstery and Bose speakers are among the premium extras in SL trim level.

All Altimas have a 4-inch LCD information screen ahead of the driver, as well as Bluetooth audio streaming.Nissan's navigation system, available for SV and SL versions, gets a 7-inch video screen and a selection of smartphone apps.

Named a Top Safety Pick+ by the Insurance Institute for Highway Safety, the Altima earned five stars from the National Highway Traffic Safety Administration for its frontal and side-impact crash testing.A four-star rating was given for rollover resistance (a calculated figure).

Availability of advanced safety technology isn't quite as impressive.Only the SL edition can be equipped with forward-collision warning that includes automatic emergency braking, for instance, and it comes in a costly option group.With the optional Tech Package, the Altima earned a Superior score from IIHS for frontal crash protection.

Still, Nissan offers a number of safety items, including blind-spot monitoring, rear cross-traffic alert, and adaptive cruise control.A rearview camera is standard on all but the base model.

Altima 2.5 SR ($24,470), the sporty trim level, includes special suspension tuning, 18-inch alloy wheels, and a power driver's seat.Design upgrades give the SR a somewhat distinctive appearance.Altima 3.5 SR ($27,990) is equipped similar to 2.5 SR, but with the V6 and LED headlights.

Altima 2.5 SV ($25,460) adds to S-model equipment such features as a power driver's seat, 17-inch alloy wheels, blind-spot monitoring, and rear cross-traffic alert.

Altima 2.5 SL ($28,570) features leather seat trim, a power passenger's seat, 18-inch alloy wheels, and Bose speakers.Adaptive cruise control, automatic braking, and navigation come in a Technology Package.Altima 3.5 SL ($32,690) is similar to 2.5 SL, but with V6 engine.

For plenty of midsize-sedan buyers, of course, that's not a drawback at all.While exhibiting a pattern of external bulges, the Altima is nevertheless cleanly designed.The sporty SR trim level derives a somewhat different look from smoked headlight housings, a decklid spoiler, foglamps, and distinctly styled wheels.

Optional leather upholstery on upper trim levels adds an appealing luxury factor.Still, the interior fails to come across as upscale or stimulating.

Impressively spacious overall, the Altima provides ample room in the back seat, thanks in part to the relatively long wheelbase.Dimensionally, though, rear legroom ranks around average for the midsize class, and passenger feet might not slide easily beneath the front seats.Most heads won't contact the headliner.

Comfortable Zero Gravity front seats, initially designed in accord with recommendations by NASA, offer plenty of head and leg space, even for a taller driver.Knee space is a tad limited by the dashboard.Acoustic glass and ample sound-deadening help keep the sedan pleasantly quiet.Measuring 15.4 cubic feet, trunk space ranks close to average.

Even in SR trim; an Altima cannot accurately be called sporty or particularly stimulating.Still, the SR, turbocharged or not, differs markedly from other Altima models.Stabilizers bars are thicker on the SR, and dampers stiffer.The suspension provides a welcome balance between passenger comfort and firm handling, without turning stiff.Other versions can yield a sense of floatiness when rolling through rough pavement.

Electro-hydraulic power steering tends to be slow, with excessive slack, though sufficiently precise.Brakes are effective, with good pedal feel.

The four-cylinder engine is wholly adequate and impressively thrifty.Acceleration is swifter with the V6, but that engine can sound a bit hoarse at lower speeds.On the highway, it's louder than expected in a sedan that's known for sedate travel.

Nissan has been a leader in CVTs, and the Altima version is impressively smooth as well as responsive.Using the virtual gear ratios in V6 and 2.5 SR models can reduce the tendency of the engine to run at high rpm, which otherwise yields a droning sensation.

Nissan's frugal four-cylinder powertrain is EPA-rated at 27/39 mpg City/Highway, or 31 mpg Combined.The SR drops to 26/37/30 mpg.A V6 Altima is EPA-rated at 22/32 mpg City/Highway, or 26 mpg Combined.

Driving impressions by Andrew Ganz, The Car Connection.James M.Flammang contributed to this report.