SAN DIEGO – Honda Motor Co. Ltd.’s Acura TSX sedan is reflective of so many Americans today.

Once a lithe little number with snap reflexes, it now is moving into middle age. Its seats are a bit wider, and it doesn’t jerk its passengers around quite so much.

Yes, like so many other midsize sports sedans that have grown up, the more civilized TSX isn’t quite as much fun as it used to be.

But don’t fault Honda and Acura for taking the “refinement” track with the TSX, which is based on the same platform as the compact Honda Civic.

Despite many years of sales success, Acura still is struggling to boost its image and once and for all join the ranks of other Tier 1 luxury brands.

The new TSX is designed to move further up the luxury ladder, closer to Japanese competition that includes the softer, more refined second-generation Lexus IS and German rival the BMW 3-Series.

It boasts a few of the usual modifications (bigger size, for instance) and some that are unusual (less horsepower).

No-shows for the ’09 launch are a turbocharged 4-cyl. mill and 2-door coupe, both of which had been rumored. And, if a Honda’s new i-DTEC diesel mill is due next year as reports suggest, the auto maker is keeping mum for now (the TSX’s twin, the Civic-based European Honda Accord, will feature the engine).

Starting with the exterior, the TSX is the recipient of Acura’s new “power plenum” shield-style grille, first seen on the cool MDX cross/utility vehicle in 2006.

Acura enthusiasts were aghast at the placement of the grille on the refreshed ’09 RL flagship, but happily the TSX’s shield isn’t quite so large – more of a shield-ette – and is a bit more in harmony with the sport sedan’s overall edgy but innocuous styling.

Most dimensions have grown, with wheelbase increased 1.3 ins. (3.3 cm) and width and interior volume up 3 ins. (7.6 cm) and 3 cu.-ft. (0.08 cu.-m), respectively.

The gain in girth is glaringly evident in a back-to-back comparison with the first-generation model.

The reflexes of the narrower outgoing TSX are more akin to those of the sporty Civic, and the sedan easily swallows up the tight switchbacks along the mountain roads here near Julian, CA.

In contrast, the wider ’09 TSX corners much flatter, and its ride is softer thanks to Acura’s first application of Showa dual-mode suspension dampers that Honda says “provide ideal damping rates at both low and high speeds.”

While some of the gruffness of the first-generation TSX is missed, the reduction in road noise and vibration is a welcome change. Installation of structural frame rails above the floor instead of below it, Honda says, make for a smoother undercarriage, cutting wind noise.

’09 Acura TSX with Technology Package
Vehicle type Front-engine, front-wheel-drive 4-door sedan
Engine 2.4L DOHC 4-cyl. with aluminum block and head
Power (SAE net) 201 hp @ 7,000 rpm
Torque 172 lb.-ft. (233 Nm) @ 4,400 rpm
Compression ratio 11.0:1
Bore x stroke (mm) 87 x 99
Transmission 6-speed manual
Wheelbase 106.5 ins. (271 cm)
Overall length 185.6 ins. (471 cm)
Overall width 72.4 ins. (184 cm)
Overall height 56.7 ins. (144 cm)
Curb weight 3419 lbs. (1549 kg)
Base price range $29,000-$35,000 est.
EPA fuel economy city/highway (mpg, est.) 20/28 (11.8/8.4 L/100 km)
Market competition Lexus IS, Infiniti G, BMW 3-Series, Audi A4, Cadillac CTS
Pros Cons
Flatter cornering Not as much fun
Roomier interior Not as nimble
Interior design Too close to cheaper Accord

The ’09 TSX sticks with a 2.4L 4-cyl. engine equipped with Honda’s signature i-VTEC intelligent variable valve timing. Going against conventional wisdom, horsepower has been pared from 205 to 201, but the auto maker promises more useable midrange power.

Fortunately, the decline in horsepower isn’t noticeable. But for those shopping on specs alone, the Acura engine falls short of the IS 250’s 204-hp 2.5L V-6 and the BMW 328i sedan’s 230-hp 3.0L I-6.

While the TSX retains a standard 6-speed short-throw manual gearbox, greater rowing effort is required than with the outgoing model, which had a satisfying snick-snick-snick operation.

Available is a 5-speed “Sequential SportShift” automatic transmission with a new straight-gate shift pattern and paddle shifters. A late afternoon test of the automatic-equipped TSX in downtown San Diego proved too maddening – traffic was too heavy and stop signs too numerous – to get a good feel for its operation.

While the ’09 TSX’s interior lives up to Honda’s high standards for fit and finish and material quality, the instrument panel’s jutting central control knob only reminds of the new, lower-priced Honda Accord’s IP, which was pinched from Acura. Less parts sharing may be required if Acura truly is going to separate from Honda and move into the luxury-car big leagues.

Interior comfort is high in both front and back seats. But the wider seats don’t hold in smaller occupants as well as those in the outgoing model.

Young, mostly male executives are the target customers.

But, after spending a few hours behind the wheel, we think the ’09 TSX might appeal more to older buyers, mimicking the aging demographic trends found when the Lexus IS grew larger and became more refined.

The TSX does move Acura closer to true luxury, but the car still could benefit from a dedicated platform, an optional V-6 and a unique interior identity.

It goes on sale next month at U.S. Acura dealers.