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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  I love this car! - 2008 Infiniti M45
  By sweiss114 - January 9 - 7:46 am

  When I was shopping for a new car, I checked out several in the price range of 50000-60000. The Infiniti M45x beats all in this range. The car has great power and acceleration, and a sporty stance. The exterior is not quite as aggressive as it could be, but whatever the exterior lacks, the interior quickly makes up for. The interior design, layout, and overall look is amazing! The ambient lighting is beautiful and the control console is like none other. The comfort is tremendous in this car and is spacier than almost any car in its class in this price range. Overall, it is a beautiful car and does everything that I need it to.

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  Cant stop driving it!! - 2003 Infiniti M45
  By Hotdog - December 24 - 2:00 am

  Ive had this car for 3 weeks now, and Ive gotten so many looks on the street! No one really knows what it is yet and thats what makes it even more fun!! The engine is really quiet even when you push it hard, and if youre not used to this kind of power, whiplashes wont be scarce events. The interior is beautiful, and it offers so much more than the BMWs and Benzs and Lexuss of the same price range. As for fuel economy, my previous car was a 1982 Buick Electra V8, so the M45 sipps gas compared to that. Not saying it has great fuel economy, but I just dont think its that bad.

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  M$% 2003 - 2003 Infiniti M45
  By bocaharv - December 20 - 2:00 am

  Have the car just 1 week. Traded a Q45T 1999. This car is delightfull. Love the voice commands & ac seats. Great value for the money. Wife has a 2002 Mercedes C320. cost about the same but this car is much more comfortable.

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  Outstanding to Own!! - 2007 Infiniti M45
  By Wendell - December 19 - 1:40 pm

  Leased this car about 3 weeks ago. Have been following this model since the redesign in 2006. When my 2003 Volvo S80 lease was about to end, I saw an special on the website. I went in to the local dealer and they were able to set me up. although I went in to get an M35, I ended up deciding on the M45 Sport. The 8 cylinder is only 1 mile per gallon different in the MPG. The power of the 4.5L is quiet but very muscular. The interior comforts are great and the overall appearance of the car bring many compliments. Got a 21 month lease on the car at about $100.00 per month more than I was paying for my S80. love driving this machine....

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  My new M45 - 2003 Infiniti M45
  By mbaworks - December 8 - 10:00 am

  For someone who liked Japanese Sport Cars, like the Toyota Supra Turbo, this car delivers quick acceleration with superb stability. The braking system is excellent which comes in handy. This car is more a sport car than a sedan.

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  Best of Class - 2004 Infiniti M45
  By theyoke - November 27 - 12:40 am

  I was passing a used car lot and saw this car, it looked interesting. The interior looked refined, comfortable and luxurious. Then I took a test drive and was hooked. Actually, test drove 3 of them and a Q within a month. This is a hard car to find and worth the effort to look. I got a black one with spoiler and the premium pkg last week. I drove it on a winding back road on Sunday. It was fantastic. The handling is exceptional on winding roads and freeways alike. The acceleration is unbelievabe and the amenities are the best in this class. The voice command system is great along with the sound system. Its a great car that you rarely see. Test drive it and youll be hooked too!

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  So far so good - 2003 Infiniti M45
  By rog - November 1 - 6:50 pm

  I just bought my M45 almost a week ago and so far I am very pleased with my ride. I just love the power this car possesses underneath its hood. I am also very careful on how I have my foot to the pedal, since this V-8 monster will definitely gulp down its gas tank. Overall, I am very happy with the build, interior and exterior wise. Also, with lots of hp, this is seriously one very fast car. The ride is pretty smooth too.

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  Great value, still not quite first tier - 2006 Infiniti M45
  By Paul Rogers - October 28 - 3:03 am

  I have come to the M45 after 12 years of owning much higher-end luxry performance cars: Mercedes SL55, Jaguar XJR, Acura NSX. The M45 won me over with the only interior design comparable to the first-tier cars, and very reasonable performance for a 4 door sedan. Exterior design is uninspiring, sharing far too much with the Nissan Altima and Maxima. Highs: interior design, wheels, ride comfort, seating room, performance capability, value. Mediums: steering response, exterior styling, exterior fit and finish, paint quality, audio Lows: interior fit and finish (relative to class); buggy XM radio implementation; rear shade is $5000 option (because it is bundled with rear video screen)

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  M45 is IT - 2006 Infiniti M45
  By bsouth808 - September 27 - 4:06 am

  This is the car to own if in the market for something under 60,000. I drove the RL, the BMW 530, and believe it or not the Corvette. Though the Corvette was nice it was not really practicable for the family situation. The power this thing has beats any others in the same bunch. With the Acura everything is standard, but there are no options to get. This thing I have has the DVD player in the roof and on the dash. With rear wheel drive you have no need for SH-AWD. It has a camera for backing up, and trust me if you have never seen this check it out. Intelligent cruise control another thumbs up it really works. Lane changing thingy needs some work. Headlights WOW. POWER POWER POWER

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  My M45 - 2003 Infiniti M45
  By PJRLITE - August 27 - 2:00 am

  Three months into my new M45 , I am generally pleased. Dash layout , road noise ( wind and underbody )and transmission delay are all points of concern . ...For $45K I should have gone with a BMW 5 series.......