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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  Infiniti Mx45 - 2006 Infiniti M45
  By Jan - July 14 - 2:13 pm

  Driving has been a pleasure so far but have not encountered any real adverse weather conditions yet. Have had to have the complete gps system replaced at 3,000 miles. None of the controls would work including the cruise control. Poses a serious threat should you be caught in some inclement weather if you cant defrost your windshield

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  Big mistake - 2006 Infiniti M45
  By HAL - July 6 - 7:03 am

  After owning from Porsches (11) to Bmws (4) and various American cars spanning over 45 years, this rates as one of the most overrated and troublesome vehicles I have owned. What makes it worse has been no factory support for these problems, which have been mostly electronics that control safety function such as ABS,Traction Control,Etc.The selling dealer service manager did everything he could to solve the problems, even improvising on his own but was limited by the factory representatives. Back to German cars, forever!

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  Luxury at a Lower Cost - 2007 Infiniti M45
  By MMM45 - June 15 - 9:20 am

  I opted out from buying the Sport model due to it being for my wife and the harsher ride. I purchased a used 2007 M45 with 18K. It has the Tech pkg & the Advanced Tech pkg. It may have the 18" wheels, but they are chrome and this car has the ground effect pkg including the spoiler like the Sport model. You cant beat the Graphite Metallic exterior and the black interior color combo! It handles great and has lots of power, though for a V8, I think there is a lot of it capped somewhere in the programming. This car is loaded with features! It has everything except the power rear seat controls. The steering, braking, balance, and power combo is superb!

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  Almost heaven - 2006 Infiniti M45
  By MR. B - May 21 - 1:36 am

  You can spend over 80 thousand or less than 30 thousand, this car gives you everything you could desire in every car of every level. The ride, the comfort, the build, the smart intelligent intergration...Nothing was left untouched about the car. For those who desire that name of lexus, and mercedes think again. This is a must have car. I am a owner of a mercedes and lexus and acura, however this car takes the prize. You have to drive it to believe it.

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  Awesome - 2003 Infiniti M45
  By Barry Jeffries - May 14 - 2:00 am

  I love the style and the 340 ponies up front put this car over the top!

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  Awesome Car - 2006 Infiniti M45
  By cre - April 28 - 7:40 am

  After owning several Infinitis over the years, this is by far the best one I have ever had. I have only had the car for about a week, but I can tell that I am going to enjoy driving this car for the next few years. It has many wonderful features and options. The car is very quick and handles great. I especially love the Rear-active Steering (4 wheel steering) and the adaptive headlights. I recommend this car to everyone looking at a new Acura, Lexus or BMW!!

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  gorgeous car, awesome power - 2006 Infiniti M45
  By abeh - April 25 - 6:20 am

  I test drove the Mercedes, BMW, Volvo, Audi, Cadillac, and finally the Infinity M45. Originally I wasnt planning on going to Infinity because I wasnt impressed with them from the outside. When the salesman brought out the new 06 M45 V8 Sport I was in love. Its sleek, stylish, and the interior leaves nothing to be desired. Its fun to drive, and as I live in the mountains, it handles curves and hills like a dream. The bose surround sound cant be touched by any of the other cars out there, and the bourbon and black leather interior is turning heads everywhere I go. Everyone wants to know what kind of car it is.

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  This is the one - 2003 Infiniti M45
  By Rick0320 - April 2 - 2:00 am

  IF you are looking for power, tech, and fun all in one package this is it. No other car comes close.

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  M45 Sport - 2006 Infiniti M45
  By AKANORM - March 28 - 3:40 am

  Leased the car mainly becuase I dont think the resale value is there. I looked at the BMW 540i and almost purchase one, but the price difference between the M45 and the BMW 540 was too significant and could not justify it to myself. Im glad I got the M45, I think the M45 is the best value out there. Its has more power then the Lexus 430 (previously owned). Its a nice car and a great value.

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  Great Sport Sedan!!! - 2006 Infiniti M45
  By Bobby - March 7 - 9:10 pm

  The 2006 M-45 Sport is a great sport sedan and I think it is the best value of all the good sedans out there. If you compare it to its real peer group, BMW 545/550,MB E500/550,AUDI S-6, it is as fast or faster, handles and brakes better, has more user features in the interior, and is less expensive! My car is loaded with Voice-activated Navigation ,Bluetooth , heated and cooled seats,DVD,6-disc CD changer, leather, 19 in. brushed aluminum sport wheels, etc. It is the best drivers sport sedan I have ever owned. The acceleration is very quick (0-60 in 5.2 sec.), the brakes are phenomenal, and the handling is very flat around fast corners.