NASHVILLE, Tenn. — Nissan has unveiled its 2013 Altima, the fifth generation of what is now the second best-selling car in the United States. In its 20 years of existence 4.4 million Altimas have been sold, but it has never challenged for sales domination in the U.S. This time out, Nissan is confident its new sedan is ready for prime time and can dethrone the Toyota Camry and achieve the lofty goal of number one.

The Altima is completely redesigned and starts life with best-in-segment fuel economy of 38 miles per gallon highway. It features head-turning exterior styling with increased aerodynamics, premium materials, and a terrific balance of ride comfort, stability and fun-to-drive attributes not generally associated with a family sedan.

Wheelbase is the same as the outgoing generation but the 2013 version has a wider front and rear track, sloping rear roofline, deep fenders, high trunk and small wheel opening gaps.

All that, combined with a new grille design and seamless bumper and projector-type headlights, creates a much bolder look. Though clearly recognizable as an Altima it’s there the similarity to its forefathers ends. Overall body weight has been reduced about 80 pounds via an aluminum hood and bumper reinforcements and expanded use of high-tensile steel.

Furthermore the coefficient of drag has been reduced by five percent by smoothing the airflow around the body and adding six air deflectors and two large underbody panels. A color palette of eight special colors help emphasize the lines of the new vehicle.

There's a new Altima for every conceivable buyer. There are four 2.5-liter four-cylinder-equipped models (2.5, 2.5 S, 2.5 SV and 2.5 SL) and three 3.5-liter V6-equipped models (3.5 S, 3.5 SV and 3.5 SL). Each step up the trim level ladder bringing more standard equipment.

Pardon the pun, but any great vehicle starts with the motor and the two powerplants Nissan offers for 2013 are outstanding in their own right. The 2.5L cylinder DOHC inline four-cylinder  develops 182 horsepower and 180 pound-feet of torque. EPA fuel economy estimates are 27 mpg city and 38 mpg highway. The other engine is a 3.5L V6 containing 270 horsepower and 258 pound-feet of torque. The V6 has fuel economy estimates of 22 mpg city/30 mpg highway.

Both engines are mounted to Nissan’s next-generation Xtronic CVT (continuously variable transmission). Nissan has historically had the best CVTs in the industry and as difficult as it is to believe, I found the new edition noticeably smoother. Some CVTs don’t let you forget you’re driving one; Nissan’s make it difficult to believe that you are. As a further “treat,” the 3.5L V6 models come with column-mounted paddle shifters with manual mode. (Full discloser — I don’t like paddle shifters. By definition, an automatic transmission means you don’t have to do anything; paddle shifters seem like fly fishing; I don’t want to work that hard.)

The 2013 Altima is a great road car. It comes standard with Active Understeer Control, front and rear stabilizer bars and a host of suspension, steering and braking technology that explains the superb handling.

As good as the new Altima is on the outside it’s even better on the inside. It begins with Nissan’s NASA-inspired “Zero-Gravity” seats. The least fatiguing seats are those that come closest to a “neutral posture” — a relaxed position that the human body takes in a weightless environment.

In side-by-side comparisons with previous seating it’s especially noticeable. A long drive while sitting in the new seats proved it. No, you’re not going to float about the cabin like Buzz Aldrin; but you sure are going to arrive more refreshed than you’d expect after hours behind the wheel.

Premium materials, be they cloth or leather, cover the seats, further decreasing driver fatigue. Depending on the model the driver’s seat is either six-way powered or eight-way powered and the front passenger seat is four-way adjustable. There’s plenty of standard and optional connectivity and navigation as well as several audio systems of various content.

Easily legible instrumentation contains the usual array of gauges, and between the large tachometer and speedometer is Nissan’s Advanced Drive-Assist Display with a four-inch LCD in-dash vehicle information display system with custom selectable settings, system warning information, tire pressure readouts, audio and (available) navigation.

For those “purists” who will only drive an “American car” it’s hard to get more American than Tennessee — the state that contains the city of Smyrna, where the Altima is produced. And just like the old Meineke Muffler Shop slogan of “you’re not going to pay a lot for this muffler," so, too, will you be able to retain all your arms and legs; base price for the 2.5 Altima starts at $21,500 and goes up to $24,100 for the 2.5 SV. The 3.5 S starts at $25,360 and the 3.5 SL begins at $30,080.

As mentioned, Nissan has set a very high bar for its 2013 Altima, especially when one considers that the midsize sedan is the most competitive segment in the industry.

Among the fierce competition in this shark tank are such warriors as Passat, Accord, Sonata, Camry, Malibu and Fusion. None of them are shrinking violets when it comes to protecting what they view as their own turf. But if the miles I’ve driven in all those vehicles have shown me anything it’s that they’re the ones who are going to have do battle with the 2013 Nissan Altima, not the other way around. Stay tuned.

To paraphrase an old saying, “It’s going to be a very sporty ride.”

— Al Vinikour