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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  Road Killer - 2006 Infiniti M45
  By Don Shea - December 5 - 7:56 am

  Best sedan to drive I know of - great handling, blazing acceleration and tremendous braking. Many compliments received. I purchased the first one in Plano, Texas and probably North Texas.

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  Best Car in Class - 2007 Infiniti M45
  By Mak - December 3 - 1:33 am

  I bought the M45 sport 2 months ago and cant be happier with the choice I made. This car handles and drives better than the competing 5 series models I drove and leaves most luxury sedans in the dust. It wasnt the value that drove me to buy this car (it is way cheaper than the beamer) but the overall package. Even the much more expensive BMW 550 doesnt deliver the luxury this car delivers, and I prefer the interior of this car. The back seat passengers have more leg-room and can actually adjust their seats. This is the first time my two kids have stopped fighting over the front seat. The younger one actually prefers the back. Overall, couldt be happier. Love, love the car.

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  best car on the market - 2007 Infiniti M45
  By h d a - November 15 - 11:46 am

  you cannot buy a better car. has all the toys that a man could want.

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  M45 more like a 2 - 2003 Infiniti M45
  By Joe Yeager - September 26 - 1:43 pm

  Been in the shop at least 15 times for repairs, 7 for the same thing. Hesitates when accelerating at low to medium speeds - great at highway speeds. Now gas gauge doesnt work, uses 1 qt of oil every 3,000 miles and pings like crazy when first started. Worst car I have ever owned.

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  4 Wheel Rocketship - 2003 Infiniti M45
  By AllenG - September 22 - 2:00 am

  This car is amazing. My previous car was a Mercedes E320. I thought that was a great car, but this car is better in every way. It handles better, classier interior, MUCH faster, and less money. The Infiniti service is on par with Mercedes. This is the car to buy!

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  awesome car i love it - 2004 Infiniti M45
  By straub - September 5 - 10:00 am

  A great car to drive from an infiniti loyal customer

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  great car - 2006 Infiniti M45
  By dl888 - August 16 - 1:10 am

  sold my MB 600S 2 1/2 months ago. test drive Lexus 300 430 BMW 525 MB 500CLS Acura RL and bought M45 Sport with tech option. It is an exciting car to drive. 14 speakers audio is fantastic.

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  Most fun sedan I have ever owned - 2007 Infiniti M45
  By Jim Cahill - August 7 - 9:36 pm

  Overall, this is a great sedan. The mileage is rated at 17 city and 23 highway and I have been averaging about 19 combined. I live in Minnesota and we had our first major snowfall yesterday. With rear wheel drive and the all season tires it did not perform well so I am having some snow tires put on. That should make a huge difference.

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  First of its kind! - 2006 Infiniti M45
  By Scott C. - July 17 - 12:00 pm

  After driving a BMW M3 for three years without a ticket, it was time to quit while I was ahead. I had a yen to trade for a luxury car but did not want to give up on the performance side. The new M45 was perfect. Beautiful, very hi-tech, and silly fast. I found I gave up very little on the performance side, but gained nearly everywhere else. Wonderful car.

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  Best car Ive ever owned - 2007 Infiniti M45
  By mike8231985 - July 9 - 5:08 pm

  I had a Mercedes E-class prior to this and was ready for something more sporty. Im in my 20s, and I think the E-Class is geared towards older people who just want comfort. The M45 is for people who like to drive hard and get thrills from speed and performance. I never thought a sedan would be as much fun/more fun as my BMW 330ci. Reliability is amazing and part of the reason I decided against buying another German car. The Infiniti fits my personality a lot better than the stuffy E-class.