NASHVILLE, TN – Car buying in the crowded midsize-sedan passenger segment just got a whole lot more difficult.

Already bursting at the seams with all-new or significantly refreshed models such as the Toyota Camry, Chevy Malibu, Volkswagen Passat, Kia Optima and Hyundai Sonata, a redesigned-for-’13 Nissan Altima enters the fray this summer, followed by a new Honda Accord in fall.

The Altima should prove a strong competitor in the field, boasting the roominess and near-luxury trappings of its rivals, while adding slightly stronger doses of performance-driving dynamics and styling verve.

However, the Altima’s greatest coup might be its best-in-segment 38 mpg (6.2 L/100 km) highway fuel economy, which is 6 mpg (2.4 km/L) better than the previous-generation model.

If the number holds up to federal tests as Nissan expects, it would put the standard-equipped 2.5L 4-cyl. Altima ahead of some others in a segment relying on optional equipment to reach the doorstep of 40 mpg (5.9 L/100 km).

Expect a combined-cycle number of 31 mpg (7.6 L/100 km) and a city-cycle rating of 27 mpg (8.7 L/100 km), engineers with the No.2 Asian brand say during recent testing of the Altima here. Our testing returned a bang-on 27.1 mpg during a short stint of city driving.

Nissan also will make available in the fifth-generation Altima its venerable 3.5L VQ V-6, which turns 270 hp and delivers an estimated fuel economy of 22/30 mpg (10.7/7.8 L/100 km) city/highway. Those numbers are 3 mpg (1.3 km/L) better than the ’12 model.

Nissan expects the 182-hp I-4 will account for roughly 90% of sales. It retains the same architecture as the QR25 engine found in the previous two generations of the Altima, but adds a variable-flow intake manifold and what Nissan calls a “smart alternator” that performs battery-charging duties when drivers are asking for the least performance, such as when coasting.

Engineers also shaved a few pounds of curb weight through the mild redesign.

In the limited time we spent behind the wheel, the transversely mounted engine pulled the 3,100-lb. (1,395-kg) sedan along quite nicely, quickly getting up to speed from stoplights and curves around residential Nashville.

Nissan engineers also keep engine clatter to a minimum, although the familiar whine of Nissan’s continuously variable transmission still creeps into the cabin.

The CVT provides 40% of the Altima’s fuel-economy story – the engine revs at just 1,450 rpm at 60 mph (100 km/h) – so there was little debate in product-planning of making a costly about-face to a standard step-gear transmission.

The folks in engineering instead redesigned 70% of the transmission. Gear ratios were spread out further to emulate a conventional 8-speed transmission; friction was cut by 40%; and software tweaks helped remedy the seeming lack of responsiveness typically plaguing CVTs.

The improvement over previous-generation Nissan CVTs is palpable, and the smoothness of the acceleration impresses. Nonetheless, we remain mixed over the CVT given the noise, vibration and harshness characteristics.

The Altima also handles as well as any competitor in the segment.

The goal, however, was to move its reputation up a notch, so engineers benchmarked models above the Altima such as the BMW 3-Series and Audi A4, which led to a redesign of the multi-link rear suspension.

The biggest change includes unique linkage connections and the latest twin-tube damper technology from ZF similar to what might be found on performance-luxury vehicles.

There’s excellent lateral stiffness, satisfactory ride comfort and an imperceptible steering- and brake-assist technology to help drivers better navigate through corners.

Our drive took place between Nashville and the Altima’s assembly plant in nearby Smyrna, a sedate stretch of road that’s the envy of every commuter north of Interstate 80. But the Altima did gobble up a few dips that would have brought others in the segment to their knees.

The Altima’s exterior styling also stretches the segment’s boundaries, following a path laid by the edgy Sonata. There’s the familiar “low and wide” look from the rear, and designers drew inspiration from a samurai’s formal coat for the grille and a Japanese temple for the roofline.

Overall, the Altima is about an inch (2.54 cm) wider and longer, giving it enviable proportions. The all-new rear-daylight opening at the C-pillar is a particularly fetching piece of styling bravado.

The Altima’s interior does not depart from the segment’s formula for roominess and touches of luxury, such as the ubiquitous and entirely unconvincing wood trim found on our $26,000 tester.

However, the car carves out some individuality with a new 4-in. (10-cm) color driver information screen located between the speedometer and tachometer, delivering with ease a 3-dimensional view of navigation data, plus audio and a raft of vehicle-safety alerts. It’s a feature you expect on a much more expensive vehicle.

The Altima also scores points with exceptionally comfortable, form-fitting seats. The auto maker says it drew upon expertise from NASA to provide drivers a stress-free seating posture that increases blood flow, decreases muscular load and reduces fatigue. They are best-in-class.

The auto maker uses the Altima to roll out its new smartphone technology called NissanConnect, which enables Bluetooth connectivity such as hands-free text messaging, Google POI searches, Pandora Internet radio and SiriusXM Satellite Radio.

Up-level models convey the information, as well as other traditional audio, navigation and vehicle settings, through a 5-in. (13-cm) color display in the human-machine interface.

Pricing for the new Altima starts at $21,500, and a loaded V-6 model eclipses $31,000, targeting a wide swath of buyers with seven available trim levels and three option packages. It arrives at dealers from Nissan’s Smyrna and Canton, MS, assembly plants in late June. Engines come from Decherd, TN.

The launch of the new Altima will be Nissan’s biggest ever; advertising will stretch from traditional to digital and heavily leverage the upcoming presidential election and professional football season.

It will take as much, because as good a first impression as the Altima makes, there’s a boisterous field of worthy competitors also vying for attention.

jamend@wardsauto.com

’13 Nissan Altima
Vehicle type Five-passenger, FWD sedan
Engine 2.5L QR25 4-cyl. with aluminum block and head
Power (SAE net) 182 hp @ 6,000 rpm
Torque 180 lb.-ft. (244 Nm) @ 4,000 rpm
Bore x stroke (mm) 89 X 100
Compression ratio 9.6:1
Transmission Xtronic Continuously Variable
Wheelbase 109.3 in. (277 cm)
Overall length 191.5 in. (486 cm)
Overall width 72.0 in. (182 cm)
Overall height 57.9 in. (147 cm)
Curb weight 3,121 lbs. (1,360 kg)
Base price $21,500
Fuel economy 27/38 mpg (8.7-6.2 L/100 km)
Competition Toyota Camry, Honda Accord, Chevrolet Malibu, Ford Fusion, Volkswagen Passat, Hyundai Sonata, Kia Optima
Pros Cons
Top-rated fuel economy Polarizing CVT
Snugly sprung suspension Too harsh for U.S. tushes?
High-tech IP Unconvincing wood trim