Overview & Reviews

Though high-end vehicles now come in more shapes and sizes than ever, the midsize luxury sedan segment remains the heart of the luxury automobile market. Nissan's luxury division, Infiniti, has been around since 1990, yet it had no real presence in this key segment until 2003, when the V8-powered, rear-wheel-drive M45 was launched. Although it offered a credible amount of luxury and performance, the original M45's relatively uninspired design and cramped interior kept it from registering anything more than a faint blip on luxury buyers' radar screens.

The last iteration of the Infiniti M45, however, enjoyed wide critical acclaim. With substantially more space, a tremendous amount of technology and comfort features, and a bold, imposing exterior design, the last M45 was a high-tech powerhouse with plenty to offer midsize luxury car shoppers. Its performance capabilities were raised significantly due to things like available four-wheel steering, a precisely tuned suspension and strong brakes. Even though the V6-powered M35 represented a significantly better value and offered potent performance, the current M45 was a swift, stylish, superbly executed luxury sedan that should be considered with the contemporary top players in the segment.

The M45 was replaced by the redesigned M56 for the 2011 model year.

Most Recent Infiniti M45

The most recent generation of the Infiniti M45 was produced from 2006 to 2010. First-year models were listed as having 335 horsepower, with subsequent models rated at 325 hp. This was due to a change in horsepower measurement rather than actual output and thus, performance was unaffected. The M45's five-speed automatic transmission had manual-shift control and a sporty rev-matching feature that imparted a particularly lively feel to downshifts.

Originally, there were two trim levels: base and Sport. Even the base car included such items as leather upholstery, driver memory functions and dual-zone automatic climate control. Stepping up to the Sport netted you 19-inch wheels, a sport-tuned suspension, active rear steering and adaptive xenon headlights. Options included such high-tech fare as navigation adaptive cruise control, lane-departure warning system and a surround sound system.

For '08, the mildly face-lifted M45 gained the option of all-wheel drive and its M45x AWD trim level. The Sport trim was also replaced that year in favor of an optional Sport package on rear-drive base models, while the navigation system was given a welcome overhaul that included a hard drive and digital music storage. It remained unchanged before making way for the redesigned M56.

The Infiniti M45's interior was well appointed and well built, with firm seats that were highly adjustable, comfortable and heavily bolstered. However, the competition in this segment was pretty intense and the M35 wasn't quite as elegant and thoughtfully engineered as some of its rivals. The quality of materials was a bit uneven, and we found that the layout of the center stack controls wasn't as clean and intuitive as it could be.

In road test reviews, editors praised the Infiniti M45 for its explosive power, sharp handling and its bounty of luxury features. Criticisms of the M45 included overly intrusive road noise and complicated center-stack controls that were hard to master. Also, we questioned the logic of buying the thirstier V8, when the M35's V6 provided nearly as much power.

Past Infiniti M45 models

The first-generation Infiniti M45 was sold for 2003 and '04 -- there was no 2005 model -- and was basically a Japanese-market Nissan Cedric luxury sedan brought over to fill the gap between Infiniti's near-luxury G35 and the larger, technology-laden Q45. Engineered for the narrow streets of Japan, the M45's cabin proved too narrow to hold corn-fed Americans comfortably, and the backseat was scant on legroom for a car of its size. Even worse, the M's exterior design was bland to a fault.

However, it was fast. The original M45 was available only with a 340-hp V8 and rear-wheel drive. Combined with big 18-inch wheels and performance tires, the M45 delivered respectable handling. Equally important, the original M45 was equipped with nearly the same number of safety features as today's model.

Cheaply priced and available with most of the luxury features found on the larger Q45, first-generation M45s generally represent strong used-car values in terms of feature content and performance. For shoppers who like the car's combination of stealthy speed and luxury, and don't need a lot in the way of interior room, the first-generation Infiniti M45 could be a good match.

User Reviews:

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  Best in Its class - 2006 Infiniti M45
  By Daniel - March 23 - 8:56 pm

  I must say I LOOOOVEE my new M45 Sedan. I opted for the Premium Pack. Sedan then the sport. Not to much difference really in suspension from what Id seen during test drive. But you cant get the heated and reclining seats in the M45 Sport. For the money the performance, design, and technology are the best out of BMW, Audi, Acura, and Lexus. If you want a performing luxury sedan go with the Infiniti M. Its nice to be able to take a 530i BMW at the stop light and win!!! And as for the lexus GS430, you can leave them in your dust Too. INFINITI, It seems Ive become a definite part of the Family. This is my third car with them and they just keep getting better with every year and model.

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  the facts and nothing but... - 2006 Infiniti M45
  By he knows - February 26 - 9:36 pm

  An exemplary combination of fit, finish, power, convenience, reliability, power, comfort and all other characteristics one would expect of a vehicle of this class and price.

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  Fun and Practical! - 2003 Infiniti M45
  By IndyDrive1 - February 26 - 2:00 am

  This car has its own "niche". I test drove one today and it did have a hint of the muscle cars of the 70s , but pampering is the order of the day. This car had a great combination of perfomance and comfort.

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  It doesnt Get Any Better Than This! - 2003 Infiniti M45
  By VOLGRAD - February 21 - 2:00 am

  Only problem on the delivery was a squeeking sun visor. To date, nothing is amiss. Even the steering is OK. (Normally needs alignment.) It is hard to imagine that the competitors could produce a better vehicle. I would recommend that any buyer of a luxury sedan should test drive the Q45.

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  Fast and Sure - 2003 Infiniti M45
  By pokey poke - February 10 - 10:00 am

  This car rocks over any luxury sports sedan at its price, and some at significantly higher prices. The V-8 steps off the line nearly as fast as my bosss boxster, but I can fit three buddies in my car and all our golf clubs. Im very happy with it. The styling gets knocked by some reviewers, but I like it, and get nice comments on its lines from folks all the time.

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  M45 Review - 2007 Infiniti M45
  By Dan - January 20 - 2:10 pm

  While this car is complete with everything, the only thing that is in need of improvement is the Sport Rims. The car runs fantastic with every possible feature, DVD, Bluetooth, navigation with voice recognition, etc. However, the roads here in New England make sense for stronger sport rims as they are built too soft and have twice caused major cracking to the wheels which had to be replaced. While this is a not necessarily a flaw, normal driving conditions in New England include potholes, and hindsight is 20/20 and I would have chosen different more durable rims, although the sport rims give a better appearance.

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  Outstanding Luxury Car - 2006 Infiniti M45
  By Prestoni - January 17 - 1:56 pm

  This is an awesome car. I have driven it about 12,000 miles and I am glad I got this car. When I need power to pass, i9t is there without hesitation. The Bose sound systems rocks. I also love the voice activated Bluetooth phone and the tons of bells and whistles.

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  Look out BMW - 2006 Infiniti M45
  By David L - January 5 - 7:00 am

  This car is a blast to drive. Its a four door sedan that reminds me a whole lot of my 350Z; only it rides a whole lot more smoothly.

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  1a - 2007 Infiniti M45
  By mboy - December 30 - 10:40 am

  After 3500 miles the M45 has been a pure joy to drive. The rear view camera works very well as does the adaptive speed control. The lane departure function can be annoying on streets that have uneven surfaces or are a bit rough as these surfaces are picked up as lines and false readings are frequent. I am about to turn this feature off. Acceleration is more than adequate and handling is superb. Fuel consumption is a bit disappointing at only 16 mpg combined. Overall a great car.

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  Great Valentines Gift! - 2003 Infiniti M45
  By Sherryb - December 11 - 2:00 am

  my new M45 is my dream come true. Super fast, sleek, and extremely reliable. Not only does it look beautiful in black obsidian with willow interior, but it has all the vital safety features that i was looking for, and more! i am so happy with it, that i am telling my friends and familty to go out and buy one. This car rocks!!!