LA JOLLA, CA – There wasn’t anything terribly wrong with the fifth-generation Hyundai Sonata, a popularly priced sedan that began chipping away at the market shares of its chief rivals.

True, the Sonata was outsold in 2009 by the Toyota Camry (and Prius), Honda Accord, Nissan Altima and Chevrolet Malibu.

But here’s the rub: All those midsize vehicles posted double-digit sales declines in 2009, while the Sonata, at the end of its multi-year lifecycle, boosted its volume 2.3% to 120,028 units, according to Ward’s data.

Not surprisingly, the all-new Ford Fusion also grew its sales to 180,671 units in 2009, reinforcing the importance of fresh product.

Now it’s Hyundai’s turn for a restyled and re-engineered Sonata in a sector destined for growth.

The sedan does not disappoint and is on sale now, ideally timed to benefit from the surging popularity of the Hyundai brand and fully capable of ratcheting up that momentum. The Sonata cements Hyundai’s near-luxury ambitions.

While most auto makers are suffering losses or posting modest growth, U.S. light-vehicle sales for South Korea’s top brand are up an astounding 39.2% for the first four months of the new model year.

The new Sonata is a dramatic and progressively styled wedge of a car that works just as well for Mom and Dad’s date night as it does for a real estate agent showing houses. It measures 1 in. (2.5 cm) longer than the previous Sonata and will be classified by the Environmental Protection Agency as a large car. It has more interior volume than each of its rivals.

The Sonata is a decidedly upscale car (like the runaway hit Genesis sedan) with a down-market price, starting below $20,000. Why buy a Lexus ES 350 for $34,800, only to have it confused with the new Sonata?

There are other compelling reasons to buy: The front-wheel-drive Sonata handles well, has a beautiful interior and offers a sophisticated new direct-injection gasoline 4-cyl. engine that delivers remarkable fuel economy in addition to class-leading horsepower (198) and torque (184 lb.-ft. [249 Nm]) among rival I-4s. The SE trim gets 2 extra horsepower and lb.-ft. of torque.

This all-new Theta II GDI represents a significant risk for Hyundai, as it is the Sonata’s only engine at launch, and there is no plan to offer a V-6. Consider the strategy a referendum on America’s true level of interest in fuel efficiency.

Later this year, a 2.0L turbocharged I-4 will arrive. In the Genesis coupe, that engine delivers 210 hp and 223 lb.-ft. (302 Nm) of torque. Expect more information about the powertrain rollout, including a 2.4L hybrid Sonata, at the New York auto show in April.

Hyundai may be smart for trying to sell the Sonata without a V-6. For the previous-generation car, the take rate for the 249-hp 3.3L V-6 was about 10%.

Likewise, 6-cyl. sales have been trending downward in the midsize segment as volatile fuel prices influence purchase decisions.

’11 Hyundai Sonata SE
Vehicle type Front-engine, front-drive, 5-passenger sedan
Engine 2.4L DOHC all-aluminum DI I-4
Power (SAE net) 200 hp @ 6,300 rpm
Torque 186 lb.-ft (252 Nm) @ 4,250rpm
Bore x stroke (mm) 88.0 x 97.0
Compression ratio 11.3:1
Transmission 6-speed automatic
Wheelbase 110 ins. (279 cm)
Overall length 189.8 ins. (482 cm)
Overall width 72.2 ins. (183 cm)
Overall height 57.9ins. (147 cm)
Curb weight 3,199 lbs./1,451 kg
Base price $22,595
Fuel economy 22/35 mpg (10.6-6.7 L/100 km)
Competition Chevrolet Malibu, Ford Fusion, Honda Accord, Nissan Altima, Toyota Camry
Pros Cons
Capable GDI 4-cyl. Shop elsewhere for V-6
Gorgeous interior Ditch the piano black
Dramatic styling Must wait for turbo 4

Still, certain performance-minded buyers will shop a V-6 in a rival sedan, and Hyundai is bound to lose some sales.

The new 4-cyl. is good, but the Hyundai V-6 delivered an extra 51 hp and sounded better, too.

GDI combustion events produce a unique clatter that engineers must dampen, lest they become annoying. In the process, many GDI engines, including that of the new Sonata, tend to sound a bit lifeless.

But it’s a Catch-22 for the powertrain team: Let drivers hear more of the intake and exhaust notes, and the unappealing sounds will be more pronounced, too.

Hyundai expects most Sonata buyers will place a higher priority on fuel efficiency than a throaty exhaust. On that front, the car is solid.

An hour-long drive through the hills east of San Diego returned fuel efficiency of close to 30 mpg (7.8 L/100 km) for a number of journalists.

In the final leg of our test drive – about 60 miles (97 km) of undulation from Temecula back to LaJolla – Hyundai staged an “MPG Challenge” and encouraged journalists to modulate throttle inputs for the highest possible mileage.

Our score of 42 mpg (5.6 L/100 km) was good enough for a bronze medal, but one hyper-miling journalist pushed the limits of credibility by turning in a score of more than 51 mpg (4.6 L/100 km), according to the vehicle trip computer.

For a non-hybrid 5-passenger sedan to achieve such mileage is nothing short of stupendous. By way of comparison, the Toyota Camry Hybrid, which starts at $26,150, is rated at a mere 34 mpg (6.9 L/100 km) in combined driving.

For the same money, Sonata buyers can score a well-equipped sport SE trim package with navigation system, sunroof, 18-in. wheels, dual exhaust and premium audio, with $1,000 leftover.

An “eco” indicator on the dash shows when the most fuel-efficient driving is employed, but it is not an active system that adjusts shift points or throttle control when lit.

The Sonata also gets Hyundai’s new 6-speed automatic transmission, which shifts smoothly but held gears longer than necessary on more than one occasion during our test drive.

The new transmission is 26.4 lbs. (11.9 kg) lighter than the 5-speed it replaces and comes with paddle shifters in the SE trim.

A manual transmission is standard on the entry-level GLS trim but, oddly, is not available on the SE.

With either the automatic or manual, the EPA rates the Sonata’s highway fuel efficiency at 35 mpg (6.7 L/100 km). In city driving, the manual delivers an estimated 24 mpg (9.8 L/100 km), while the automatic lags behind at 22 mpg (10.6 L/100 km).

Helping boost fuel efficiency are low rolling resistance tires, a low-friction driveline, electric power steering and the loss of 130 lbs. (59 kg) from the previous Sonata’s curb weight.

The sleek aerodynamic shape of the body (springing from Hyundai’s new “Fluidic Sculpture” design language) produces a relatively low 0.28 coefficient of drag, compared with 0.32 on the old car.

The suspension (fully independent MacPherson struts up front and a multi-link layout in the rear) provides a steady feel in most driving conditions, with improved body rigidity and less body roll than in the previous car. Both the steering and suspension are tightened for the SE trim.

Standard safety features include electronic stability control, traction control, active front head restraints and six airbags, including side curtains. The Insurance Institute for Highway Safety gives the Sonata a “Top Safety Pick” for protection in side, rear and rollover crashes.

The interior is stylishly appointed and stands toe-to-toe with every player in the midsize segment based on material selection, comfort, aesthetics and ergonomics.

Fit and finish was flawless in the two models evaluated here, and attention to detail is evident. Even something as innocuous as the center armrest displays a sense of masculine style to occupants in the backseat. Stitched leather across the top flows down to the base of the armrest, which bulges as it tapers downward, like a body builder’s physique.

Leg room in the second row is plentiful, and three head restraints improve safety for backseat occupants. Soft surfaces abound, and seats are extremely supportive. The trunk is cavernous and is better isolated from the cabin for a quieter ride.

Quibbles are few. An average-size adult male cannot fit in the middle seating position in back without hitting the ceiling with his head, and the top-end Limited model offers too much high-gloss piano black trim on the doors and center console.

The sales mix is expected to be 60% GLS (base), 30% Limited (top line) and 10% SE (sport).

Hyundai produces the new Sonata and its 2.4L I-4 at its plant in Montgomery, AL. The new 6-speed automatic transmission will come from the Kia Motors Corp. plant in West Point, GA, this summer. Pricing sheets on several salable vehicles driven here list Korean content at 58% and U.S./Canadian content at 41%.

The auto maker has plenty to offer with the new Sonata, in addition to a great warranty and an Assurance program (through the end of the year) that lets buyers return the car if they lose their job and can’t keep up the payments.

Hyundai isn’t projecting sales for the new Sonata, but count on it climbing in rank amid the best-selling midsize cars.

tmurphy@wardsauto.com