SEATTLE – Debuting in 2002 as an ’03 model, Nissan Motor Co. Ltd.’s Infiniti G35 coupe instantly became one of the sexiest vehicles available in the U.S., at least for less than $40,000.

The sinuous lines and low-slung stance of the G coupe turned heads, and unlike its cousin the Nissan 350Z, did so without a lot of garish ornamentation.

Nissan thankfully has left the original design language basically intact with the new G37, although the auto maker is quick to note the sheet metal of the 2-door, including the undulated hood, is changed from the previous generation G35 coupe and shares just the door handles with the new G35 sedan, which debuted last fall in the U.S.

The big story with the new G37 is under hood, as Nissan’s well-known and much-lauded 3.5L VQ V-6 (a 13-time Ward’s 10 Best Engines award winner) grows 0.2L in displacement, upping horsepower to 330 from a maximum 293 in the old G coupe and 306 hp in the current G35 sedan.

The outgoing G35 coupe was no slouch in the power department, so the extra horses are indiscernible during the test drive.

But the strategy shows Infiniti is not backing down in its fight with BMW AG for top sport-coupe honors.

In the horsepower wars, Infiniti has usurped BMW’s 3-Series coupe – for now, with the 335i making 30 fewer horses than the new G37, which hits U.S. dealers Aug. 21. Infiniti, however, considers the 230-hp 328i the G37’s direct competitor.

The displacement boost comes at no cost, as Infiniti proudly contends the bulked-up VQ is cleaner-burning and more fuel efficient than the 3.5L it replaces, thanks in part to the new Variable Valve Event and Lift (VVEL) timing system.

While conventional engines control air intake using a throttle valve, VVEL does this directly at the intake valves, continuously controlling their valve events and lifts.

VVEL works in tandem with Nissan’s Continuous Valve Timing Control (C-VTC) system to govern the valve phases, resulting in more efficient airflow through the cylinder and significantly improving responsiveness, Nissan says.

In addition to better performance, the new engine emits up to 10% less carbon dioxide.

“It gives us the absolute best adjustment for the best horsepower, fuel economy and emissions,” with the flexibility to tailor the torque and horsepower curves, says Randy Fior, regional product manager-product planning.

Based on the Environmental Protection Agency’s new fuel-economy ratings (taking effect in ’08), the addition of VVEL nudges the automatic-equipped G37 to 18 mpg (13 L/100 km) city and 24 mpg (10 L/100 km) highway, an increase of 1 mpg (0.42 km/L) for each from the previous automatic G coupe and an extra 1 mpg in the city than the current G sedan with automatic gearbox.

Also, the boost in power comes with 40% lower hydrocarbon emissions thanks to VVEL.

That’s all well and good for the 10% of customers concerned about the green quotient when shopping a car of this nature. However, this market is about style and speed – both abundant in the G37.

Buyers can match the 3.7L V-6 to either a 5-speed automatic, new with available magnesium paddle shifters and downshift rev-matching, or 6-speed manual transmission.

Nissan has managed to work out most of the bugaboos Ward’s staffers have noted about the manual during previous 10 Best Engines G35 testing, such as the annoying clutch vibrations at moderate to high engine speeds.

Nissan modified the shifter’s linkage and isolator to reduce vibration and revised the dynamic damper to curb clutch quivering.

The cabin could use a tad more noise damping though, to quell the racket (our only real complaint) from the combination of summer tires and some less-than-perfect pavement here.

The clutch also isn’t quite as stiff in the G coupe as it is in the G sedan, which might help Infiniti meet its goal of attracting more women buyers. (Nissan officials say the ’08 G sedan will receive these same modifications.)

’08 Infiniti G37 Sport 6MT
Vehicle type Front-engine, rear-wheel drive 2-door coupe
Engine 3.7L DOHC V-6 with aluminum block/heads
Power (SAE net) 330 hp @ 7,000 rpm
Torque 270 lb.-ft. @ 5,200 rpm
Compression ratio 11.0:1
Bore x stroke (mm) 95.5 x 86
Transmission 6-speed manual
Wheelbase 112.2 ins. (285 cm)
Overall length 183.1 ins. (465 cm)
Overall width 71.8 ins. (182 cm)
Overall height 54.9 ins. with 19-in. tires (139 cm)
Curb weight 3,668 lbs./1,664 kg
Base price range $34,250
EPA fuel economy city/highway (mpg) 17/26 (13.8/9.0 L/100 km)
Market competition BMW 3-Series, Mercedes CLK, Audi TT

There are no quibbles with the handling, as the coupe’s tires confidently grip the pavement. The steering, which some may find too light compared with the 3-Series, is nicely weighted, with only slight play in the steering wheel.

The double-wishbone front and multi-link rear suspensions have 45% greater lateral stiffness over the old G coupe, providing for a sporty-but-not-jittery ride, as bumps are well absorbed.

The G coupe’s interior carries over the sporty, inviting look of the sedan, with the same sharp aluminum “Washi” trim that resembles Japanese rice paper as one choice (the other option is a beautiful African Rosewood).

Interior panel fits are tight and precise in the pre-production models driven here.

Cupholders in the doors adequately ensconce water bottles, but the square center console cupholders leave them wobbling.

Interior room is sufficient up front, but the backseat is cramped, typical of a vehicle in this class.

The ’08 G37 is available in three trim levels. Pricing begins at $34,250 (not including $715 destination and handling), up $800 over last year’s model. However, officials say that includes standard satellite radio, push-button ignition and a more powerful engine.

A popularly equipped G37 Coupe Journey midrange model with a premium package, including a Bose sound system, Bluetooth hands-free phone capability and heated front seats and side mirrors, is $38,200 sans shipping charges, an increase of $900 from the ’07 model.

Officials estimate about a $3,000 cost advantage over the BMW 328i, which begins at $35,300 for ’07.

Infiniti won’t provide sales projections for the new G coupe.

But the horsepower bump, more user-friendly manual gearbox and reasonable price increases could keep sales of the model on an upward trajectory for at least a couple years.