2003 INFINITI M45 Reviews and Ratings

Sedan 4D

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Sam Moses

The new Infiniti M45 is a great piece of equipment. It's very well engineered, and may be the highest combination of smooth and fast in a mid-size luxury car ever to come down the pike. BMW, Mercedes, Audi, Jaguar and Cadillac have nothing for the M45's silky 340-horsepower engine.

The 2003 Infiniti M45 plays its dual role well, but we have trouble deciding whether it is a luxury car or a sports sedan, Its styling doesn't help, offering little distinction.

Model Lineup
There are no separate M45 models, so the powerful V8 with its smooth five-speed automatic transmission is what you get. But it's not all. For the base price of $42,300, more great features come standard: the same high-quality leather as in the flagship Q45, a 225-watt Bose premium sound system with satellite-ready AM/FM radio and in-dash 6 CD changer, Vehicle Information System with large LCD screen, skid control (VDC, for Vehicle Dynamic Control), dual-zone climate control, high-intensity xenon headlamps, 18-inch alloy wheels with W-rated tires, and last but definitely not least, front-door side airbags and four-door curtain airbags.

The Comfort and Convenience Package ($950) includes memory seats, electrochromic mirrors which are heated and reverse-tilting on the outside, the HomeLink remote system and a tire pressure monitor.

The Technology Package ($2700) includes the DVD navigation system and Intelligent Cruise Control, which uses lasers to maintain the distance from the car in front of you by controlling the throttle.

The Premium Package ($2200) includes seats that are cooled as well as heated, a sunroof, and voice recognition system for climate, audio and navigation control. Chrome wheels can be added to this package for another $1000.

Stand-alone options include the sunroof ($1000), natural maple trim ($300), rear spoiler ($540), satellite radio ($400) and all-season tires (no extra cost).

The Infiniti M45 is more than a sleeper, it's invisible. Cops would kill for this car. Infiniti uses the word 'distinctive,' which is a giant semantic stretch, because while the whole car might be distinct in its class, it's a long way from being visually distinct. Infiniti also describes the styling as 'chiseled,' and in places one might agree, but that doesn't make the M45 likely to be noticed. The twin tips of the exhaust pipe are about the only thing that looks hot. And probably the optional rear spoiler, which we haven't seen but would order with the car if we got one, just because it so desperately needs the statement. Thank heavens for the great-looking eight-spoke alloy wheels, which come standard in painted titanium or optional in chrome.

The M45 is not unattractive, just uninspired. The sheetmetal comes straight off the Gloria sold in Japan, where styling tastes (and car names) can be curious. So the overall lines of the car are inherited from a design never intended to appeal to buyers in the U.S., whether of midsize luxury cars or sports sedans. The roofline is totally prosaic. The lines don't flow, they just sort of exist, spreading horizontally across a front end that's dominated by an unimaginative grille stretching like a forced grin between the headlamp units, three horizontal beams per side with almost no angle. Underlining this spread, literally, is a long dark horizontal air intake.

The molded front and rear body-colored bumpers are new, and represent a designer's valiant attempt to coax the eye into thinking the whole shape is chiseled, but another adjective for the bumpers might be chunky. The rear bumper becomes a smooth part of the deck, leaving only the simple taillights and the license plate recess for definition; and the front bumper looks a bit like a guy with a pinch of snuff inside his bottom lip.

The M45 looks much better in silver than black, because of its dire need for definition. It comes in five other colors, some of which might look better yet.

Ah, relief from the demands of visual distinction. Comfort, convenience, function and ergonomics are the priorities of a car's interior, and the M45 fares much better on these counts.

The M45 uses the full-size Q45 chassis, but its overall length is three inches less. Legroom is still decent in front, but five inches have been lost in the rear. Wide rear doors make entering relatively easy, however.

The exterior dimensions of the car are a bit unusual; it's relatively long, tall and narrow; a 2003 Honda Accord, for example, is a couple inches lower and wider. So the M45 has good headroom front and rear (although our rear-seat passenger said the roofline made him feel claustrophobic), but it's squeezed on shoulder room. We first encountered this when we reached down to adjust the standard 10-way power seat; our left wrist nearly got wedged between the seat and the door.

The front seats are on the firm side: not uncomfortable, but not especially relaxing, though power lumbar support is always nice to have. We might call them sporty if there were more bolstering.

Heat in the front seats is standard. An optional cooling system for the seats blows cool air through the pores in the leather. It sometimes feels like you have a hole in your pants. It should be the hot ticket in humid climates, especially during that period before the interior cools down.

The M45 offers voice recognition, but we had trouble getting it to understand us. We also did not care for the leaf on the LCD screen of the Vehicle Information Center that indicates instantaneous fuel mileage; when you're coasting it's green, and when you get on the throttle the leaf progressively turns a smoggy gray, evidently to remind you that your 340-horsepower automobile is polluting the environment. The actual mileage numbers are there, but they're so small you can't read them.

The driver's space is tidy and sporty. There's a great four-spoke steering wheel with a nice thick rim, fairly small diameter, and controls for audio and cruise control. Four gauges, a big speedo and tach, smaller gas and temp, are laid out as cleanly as they come, and are backlit at all times. On the floor there's a solid dead pedal, and on the door there's an armrest that fits perfectly. The dashboard slopes pleasantly toward the windshield, with reasonable dials and buttons including a control for the information center, and the Infiniti trademark clock is small and discreet. There's a modest amount of smoky maple trim, most of it on the console.

In addition to the two-stage airbags, important standard safety features include side thorax airbags in front, curtain airbags front and rear, and active front headrests.

Driving Impressions
Performance in a mid-size car doesn't get any better than the new Infiniti M45. For this price, most other midsize luxury cars offer V6 engines, so the M45 starts the game with a hole shot. Rear-wheel drive is another strength, giving the M45 a real advantage over front-wheel-drive sedans.

The acceleration will knock your socks off, with a massive 333 foot-pounds of torque at 4000 rpm to go along with the 340 horsepower. (Torque is that force that thrusts you away from intersections.) But the high-tech V8's continuous variable valve timing makes the power delivery so smooth and steady there's nothing wild about it. The best part might be catching the looks on the faces of the drivers around you, who would never suspect something that looks so pedestrian could vanish so quickly. The M45 is lighter than the Q45, which is already a fast luxury car, and its final-drive gear ratio is numerically higher than last year's Q, so flight is effortless.

The five-speed automatic transmission is superbly compatible, delivering dazzling smooth upshifts and kickdowns. It's right on the money when driving hard. At slow speeds, between 20 and 40 mph, easy on the gas, it shifts invisibly, imperceptibly. You couldn't ask much more from an automatic transmission in a car like this.

That's assuming you don't care about a manual mode. The manual mode in this tranny might as well be a write-off. But it's no great loss with the M45, which doesn't beg for its use. It's just not programmed for serious sporty use. Full-throttle upshifts have a lag time in the manual mode that doesn't exist in the automatic mode. And, totally unlike the sensational and drop-dead gorgeous new Infiniti G35 Sport Coupe (introduced at the same time), the M45 manual operation is over-ridden by a chip that shifts up and down on its own. Worse, the digital readout indicating the gear doesn't always change. In manual mode, we went from third gear to first (slowing to a stop), then to second to third (accelerating), to a final kickdown to second (passing), without ever touching the lever, and without ever seeing the number 3 on the dash change.

The brakes are big vented discs, and earn great marks. The ABS was as solid and true as any we've felt in recent memory. We made a full panic stop at 70 mph, and they were very busy, very firm, very quick and very true, with only light pulsing transmitted to the steering wheel. The M45 is equipped with Electronic Brake Distribution (distributes the braking force to the tires that have the best grip), which is always a good thing to have. It also comes with Brake Assist, which senses a panic stop and applies braking harder or longer than your foot signals.

'We pushed the suspension to the limits of control and stability,'said an engineer at the M45 introduction. With 340 horses' worth of potential to get in trouble, this level of development is a good thing. It's fully independent, with struts in front and links in rear, and sport tuned. Unlike the Q45, which has three shock absorber settings from the cockpit, the M45 lives with just 'firm.' It's a very high quality of firmness, never harsh or uncomfortable. It erases most of the rough and patchy stuff, and stays the same degree of firm, keeping the car on an even keel no matter what the surface. You know the ride means business.

We didn't push the suspension that far, but we drove it as hard as we've driven some other luxury sedans, and it passed with flying colors. Although the track (the distance between the left and right tires) isn't very wide, the 18-inch wheels and W-rated tires help it handle nicely in the curves, and the speed-sensitive rack-and-pinion steering provided good feedback and didn't feel soft. If an Impala SS handled this well (not to mention accelerated this quickly), people would think it was the greatest car in the world.

The 2003 Infiniti M45 offers great value and quality, with its impressive list of standard features that are luxury options with other cars. Its awesome V8 and superb electronically calibrated transmission deliver unparalleled quickness and smoothness. The styling casts no image, but if you can live with that, more power to you.

Model as tested
Infiniti M45 ($42,300)
Basic Warranty
4 years/60,000 miles
Assembled in
Tochigi, Japan
Destination charge
Gas guzzler tax
Base Price
Price as tested
Options as tested
Technology Package ($2700) includes DVD navigation system, laser-based intelligent cruise control, Vehicle Information System with 7-in. LCD; Premium Package ($2200) includes climate-controlled (heat and cool) seat, sunroof, voice recognition system for climate, audio and navigation control; Comfort and Convenience Package ($950) includes memory seats, electrochromic mirrors which are heated and reverse-tilting on the outside, compass, HomeLink remote system, tire pressure monitor, full-size spare tire on matching alloy wheel

Model Line Overview
Model lineup
2003 Infiniti M45 ($42,300)
Safety equipment (standard)
two-stage airbags; front side thorax airbags; front and rear curtain airbags; active front headrests; ABS with EBD and Brake Assist
Safety equipment (optional)
4.5-liter dohc V8
five-speed automatic with manual mode

Specifications as Tested
Sojourner leather, Bose premium sound system with satellite-ready AM/FM radio and in-dash 6 CD changer, Vehicle Information System with large LCD screen, Vehicle Dynamic Control, xenon headlamps, 18-inch alloy wheels

Engine & Transmission
4.5-liter dohc V8
Drivetrain type
rear-wheel drive
Horsepower (hp @ rpm)
340 @ 6400
EPA fuel economy, city/hwy
Torque (lb.-ft. @ rpm)

Brakes, front/rear
11.4-in vented disc/11.5 in. vented disc with ABS
Suspension, front
independent, strut, stabilizer bar
Suspension, rear
independent, multi-link, stabilizer bar

Seating capacity
Head/hip/leg room, middle
Head/hip/leg room, front
Head/hip/leg room, rear

Fuel capacity
Trunk volume
Turning circle
Towing capacity
Track, front/rear
Ground clearance
Curb weight

J.D. Power Rating
Overall Quality Not Available
Overall Quality - Mechanical
Not Available
Powertrain Quality - Mechanical
Not Available
Body & Interior Quality - Mechanical
Not Available
Features & Accessories Quality - Mechanical
Not Available
Overall Quality - Design
Not Available
Powertrain Quality - Design
Not Available
Body & Interior Quality - Design
Not Available
Features & Accessories Quality - Design
Not Available

Overall Dependability Not Available
Powertrain Dependability
Not Available
Body & Interior Dependability
Not Available
Feature & Accessory Dependability
Not Available

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J.D. Power Rating Legend
Among the Best
5 / 5
Better than Most
4 / 5
About Average
3 / 5
The Rest
2 / 5

* The J.D. Power Ratings are calculated based on the range between the car manufacturer or car model with the highest score and the car manufacturer or car model with the lowest score. J.D. Power generates a rating of a five, four, three, or two. If there is insufficient data to calculate a rating, “Not Available” is used in its place.

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