Infiniti M45 Sport

Infiniti M45 Sport - What an improvement. The previous car (introduced here for 2003) was a modified version of the Japanese-market Cedric/Gloria large sedan, and along with looking pretty stodgy, it lacked interior space, even for front-seat occupants if they were tall. Nevertheless, the old M45 found happy customers at a rate of about 400 to 500 a month, drivers who loved the silky snarl of that 4.5-liter V-8 along with its torquey thrust. There isn't much that 340 pound-feet can't cure.

The latter is an electrically powered system that produces a brief surge of opposite-phase steering (the wheels turn right about one degree when you turn left) to induce quick turn-in, then switches to same-phase steering (also about one degree) to stabilize the car in mid-bend.

All models have leather furniture, but the Sport model has more aggressively bolstered seats with double-stitched seams, and they proved quite supportive and comfortable in use. Infiniti claims the rear-seat room to be on a par with that of the Lexus LS430 (at 46 cubic feet, the M45 has two fewer than the Lexus), and sure enough, we found space back there tolerable even for a six-foot-five passenger. However, the rear center seat is much less inviting, with a broad transmission tunnel consuming much of the floor space, forcing the middle passenger to splay his legs and have his feet share the front seatback cutouts with the outboard passengers.

Any doubts about the amount of space up front were instantly erased by the fully adjustable seats and abundant legroom. Ahead of the driver is a gauge cluster with big electrofluorescent faces and bright red needles that produce a glow in the gauge's perimeter ring to accentuate their position. The sweeping, wave-shaped dashboard has a shallow contour angle that makes the surfaces recede from the occupants, thus increasing the perception of space. All in all, it is a pleasant environment.

The V-8 has plenty of torque and a mellifluous exhaust note, and it wafts the car away from rest in a manner that is responsive and effortless. Accompanying the husky engine are a tightly calibrated torque converter and excellent throttle response. When you touch the accelerator, the car simply moves off smoothly, feeling much lighter than its two-ton fighting weight might suggest. It shifts smoothly, too, and the five-speed automatic can be operated manually via the leather-clad selector if so desired. After trying it out, we felt manual shifts were quicker, so that's how we conducted our acceleration runs.

That manual-transmission override is good for unwinding mountain passes, too, where it actually blips the throttle during downshifts, just like a good automated manual system. But we soon discovered that the adaptive transmission logic—when left in automatic—interprets your intentions accurately and performs so well in that mode that one soon forgoes the manumatic system in order to keep one's hands on the wheel. During protracted periods of brisk driving, the car will hold onto a gear even when you drop off the throttle in preparation for a corner entry, running the car against the engine at high revs as you bend it in. Then it will pick up the throttle in the same gear for a strong drive out of the curve. Trust us—it's hard to fool this amazingly intelligent gearbox.

The limits are high in this car, and the speeds attained while playing in the mountains are significant enough to ensure grave consequences if you get it wrong. Having said that, we think the M45 feels remarkably organic at the controls when being hurried along. It turns in willingly and hangs on tenaciously. The steering is naturally weighted and wonderfully precise. Like its G35 sibling, there's some trailing-throttle oversteer to be had in tight turns, but just as in that car, the slide is easy to catch.

The M45 Sport comes with xenon headlights and climate-controlled front seats, so its Journey package only adds the balance of those items. A Technology package adds DVD navigation, intelligent cruise control, a five-channel DVD Bose Studio Surround stereo with 14 speakers (two in each front seat) that has to be heard to be believed, a lane-departure warning system, and XM satellite radio.

Infiniti spokesmen are talking about prices that start in the high-30s for the M35, and from the high-40s for the V-8-powered version. We drove the V-6 model at the car's intro and found it to be a sweet piece. Then we drove the V-8, and all we can say now is: If you've got it, flaunt it.