Used 2008 INFINITI G37

It happens on lap 4. That's when the difference between Infiniti's 2008 G37 Coupe and BMW's 2007 335i Coupe crystallizes.

All at once the BMW coupe that we've considered the leader in its class finally decides it's had enough. With its oil temperature pinned at 300 degrees F and its coolant temperature climbing rapidly, the turbocharged Bavarian wonder engages its limp-home mode and we crawl pathetically back to the pits.

This all-too-dramatic demonstration of Japanese-versus-German engineering occurred at Nissan's Arizona Test Center, where Infiniti invited a select group of journalists to drive the 2008 Infiniti G37 Coupe back-to-back with Germany's best. The limp-home part, well, that wasn't part of the plan.

In fairness, both cars had experienced a relentless pounding by journalists with a profound absence of mechanical sympathy before the BMW finally succumbed to the desert heat. But the flogging had been similarly abusive to both cars, and the Infiniti G37 never showed any signs of weakness.

Major hardware changes
The 2008 Infiniti G37 Coupe is a fully updated version of the G35 coupe that put Infiniti on the map as a serious player in the market for premium sporting coupes. There's a new engine, new front suspension, updated styling both inside and out, and slightly altered dimensions.

The real news is the power plant, which received an increase in displacement to 3.7 liters thanks to a 4.6mm increase in stroke. Nissan's Variable Valve Event and Lift (VVEL) now alters valve timing and lift on the intake valves. Compression is increased from 10.6:1 to 11.0:1. These tweaks combine to increase output to a projected 330 horsepower and 270 pound-feet of torque. That's 30 hp more and 30 lb-ft less torque than BMW's 335i coupe. It represents an improvement of 55 hp and 2 lb-ft over the current G35 coupe's 3.5-liter V6.

Transmission options include a five-speed automatic, which is shared with the G35 sedan but includes a new calibration and modified torque converter characteristics. It also comes with shift paddles behind the steering wheel. Alternatively, there's a six-speed manual that is modified from the sedan to reduce vibration. Its clutch is also refined for smoother engagement. The test car we drove, however, featured the G model's five-speed automatic transmission.

The basis for the G37 is Nissan's revised FM (Front Midship) platform, which now boasts a 36-percent increase in rigidity over the G35 coupe. The front double-wishbone suspension now has a single, lower ball joint instead of the previous double ball-joint arrangement in order to reduce steering kickback. Rear suspension remains a multilink setup.

When the G37 is equipped with a sport package (as was our test car), it will feature the largest-diameter brake rotors in the segment. Fourteen-inch rotors are stopped by four-piston (two per side) front calipers. The rear setup will include fractionally smaller 13.8-inch rotors and conventional single-action two-piston calipers. In dynamic bench tests, the larger front rotors helped reduce brake temperatures by 100 F compared to the G35's sport-package brakes, which should translate directly to better fade resistance.

Four-wheel active steering (4WAS) steers the rear wheels up to 1 degree based on input from an array of sensors, and it will be available on coupes with the Premium Package. Adding in small amounts of rear steering effectively changes the overall steering ratio between 12:1 and 20:1. Rear steering is currently a $1,500 option on the 2007 Infiniti G35 Sedan, so we expect a similar price structure for the coupe.

New styling inside and out
The coupe's proportions remain the same, but there are significant detail tweaks that differentiate the newer, more muscular G. The grille now features Infiniti's signature double arch, the headlights and taillights are L-shaped and the rear deck incorporates an integral spoiler. There's also a distinct character line running the length of both sides of the hood.

Dimensionally the G coupe remains low and wide. Overall length is up about one inch while width and height change only 0.2 and 0.1 inch, respectively. The wheelbase is still 112.2 inches — considerably longer than both the BMW 335i and Lexus IS 350 sedan.

Anyone comfortable with the current G35 will feel right at home in the G37. Most of the hardware looks to have been lifted directly from the 2007 G35 sedan, including the seats, shift lever and steering wheel. The basic layout is the same as well, with a rounded door panel melding into the dash. Aluminum trim is plentiful — from the doors to the pedals with the Sport Package. And there's the Infiniti-signature oval analog clock built into the dash.

The instrument panel still moves up and down as the steering wheel's tilt is adjusted, but the magnesium shift paddles (right for upshifts, left for downshifts) do not turn with the wheel. The steering wheel on the Sport Package car we drove included audio, cruise control and Bluetooth buttons and had a satisfyingly fat leather-wrapped rim.

The sport seats still use an asymmetrical design with a small bolster in the middle of the driver seat and adjustable thigh extensions. The seat adjustment controls have moved from the side of the center console to more conventional placement on the outside of the seat bottom cushion.

Giddyup
From the first corner driven in anger, it's easy to sense the G37's focus. There's firmer damping and better body control than in the BMW 335i. More impressive is the steering, which offers a perfect compromise of surface feel, steering effort and feedback. This makes the G37 more intuitive and better behaved at the cornering limit than the BMW — and the car we drove hadn't even been fitted with the optional four-wheel steering.

The engine, despite its longer stroke, retains the 7,500-rpm redline of the G35 sedan and makes genuinely usable power at high rpm. In tight corners the G's viscous limited-slip differential puts power down consistently through 245/40ZR19 rear rubber. Infiniti staggers the tires so the front gets smaller 225/40ZR19 tires. Both the 19-inch wheels and limited-slip differential are exclusive to the Sport Package.

It's clear when driving hard that Nissan is keenly aware its competition has upped the bar. The improvements to the G37 are shrewdly focused in areas which help the G compare favorably in exactly the conditions we were given to test the cars — on a racetrack. With the Sport Package comes stiffer springs, more aggressive dampers and larger antiroll bars. We'll withhold judgment about the G's ability to adapt to real-world driving as brilliantly as BMW's 3 Series until we're able to drive them both on the street.

One area in which we know the G falls short is the shift lever for the automatic transmission, which must be toggled forward for upshifts and backward for downshifts — the opposite of BMW practice. We've always liked pulling back on the lever to trigger the next higher gear as acceleration drives us into the seat, as if we were shifting from 3rd to 4th gear. Pushing forward on the lever to downshift under braking is similarly intuitive.

Of course, if you use the shift paddles, none of this matters. Downshifts are executed with a perfect rpm match — a rare and impressive achievement in a transmission with a torque converter.

The question remains whether the G37 Sport will match the acceleration of the BMW 335i, which hits 60 mph in only 4.8 seconds and trounces the quarter-mile in 13.3 seconds at almost 106 mph. Our seat-of-the-pants assessment says that the G37 isn't quite up to that task, due mostly to its torque deficit, fewer gears (the Bimmer has a six-speed automatic) and heavier estimated weight (3,682 pounds vs. 3,571 pounds).

But anytime the going gets twisty and you're driving in the upper reaches of the power band, the G will leave the 3 Series in its wake with better top-end punch and a more performance-focused chassis.

Get yours
G37 coupes will hit dealers on August 21 of this year. Infiniti PR folks were characteristically tight-lipped about pricing, which won't be announced until just before the on-sale date.

If Infiniti follows tradition, however, it will undercut its German competition in price while offering similar or better performance. Currently, that means a G37 sport coupe with the five-speed automatic transmission will have to tally less than $44,000 — an easy task considering the current car with these options rings up a $35,750 tab.

More importantly, it probably won't ever limp home.

Edmunds attended a manufacturer-sponsored event, to which selected members of the press were invited, to facilitate this report.