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:

• 

  Great performance and fun driving - 2007 Infiniti M45
  By KS - February 7 - 7:16 pm

  Just leased 2007 sport model with techno package and aerodynamic kit black on black and must say it is one hell of a car. I have been looking for a while and narrowed my choices down to BMW 530i sport and Infiniti M45, I was leaning more towards Infiniti although it was more expensive than BMW but I was able to get a great deal and all the options I was looking for. This car feels expensive and it is a blast to drive! The engine is so smooth and the exhaust growl makes me want to floor it every time. Even when I pull up to Mercedes S class or BMW 7 series they cant help but stare at my Infiniti and then I leave them in my dust.

• 

  So Smooth! - 2004 Infiniti M45
  By m45 owner - January 28 - 10:00 am

  Giant engine thrust and silent cabin, clean understated lines, comfortable appointments and no defects in 5,ooo miles, better than 01 M Coupe, 02 Benz E previously owned. Narrow width and cabin isolation make it good city car, power and wheelbase a fine highway cruiser. At cruise cont. 60mph got 28mpg. Very pleased. Super low price.

• 

  Charlotte NC - 2006 Infiniti M45
  By JP - January 26 - 3:36 pm

  Fun car to drive, AC seats are awesome, my wife says everyone stares at the car when she takes it out but its really her. I have the sport package and it is great, I also have a 1 yr old and do not suggest the car as a alternative to the minivan

• 

  Best all-around performance sedan - 2006 Infiniti M45
  By calsteamer - January 22 - 9:00 am

  I have spent the past 6 months trying to decide on new car. I tested all comparable cars (BMW 545, Lexus GS430, Mercedes E500, Cadillac STS), and this was by far the best car for the money. Finnaly, a car with Japanese reliability that drives like a german car.

• 

  Best Sports Car + Luxury Sedan Ever... - 2006 Infiniti M45
  By Maanav Patel - January 1 - 4:56 pm

  Excellent Power + Handling, Great look inside and outside..it beats Beamer, Benz, and obviously Jag..

• 

  Best car Ive ever owned!!!!!!!!!!!!! - 2003 Infiniti M45
  By cjeder - December 27 - 2:00 am

  If you are looking at cars in the $35,000 or higher price range you MUST drive this car before making a purchase. I leased mine from Infiniti of Kirkland and my payment is less than most cars in the $35000 range. What a deal! Driving this car is like driving a hand- made, top of the line Bentley. And the 340hp V-8 is truly magnificent. Dont cheat yourself by paying more for a BMW of Lexus....drive this car first.

• 

  Refinement Needed - 2003 Infiniti M45
  By Roadglide99 - December 2 - 2:00 am

  Well the ergonomics could be better. The shifter, cup holder and armrest need to be reconfigured. So does the CD player (single in-dash is preferred). I have 3,500 miles on the car and I had a problem with the Trans. getting stuck in 2nd. gear @1,200 miles. Tried everything, finally shut the engine off and restarted, appears ok. The dealer tested it repeatitally with nothing found (the trans. is lazy while in automatic mode, when stepping on the gas to down-shift and pass). Oh the gas milage does stink, and I dont drive it wildly, ok very seldom... getting about 18mpg.

• 

  One major flaw a buyer should know about - 2003 Infiniti M45
  By l. Banks - November 18 - 10:03 am

  The only major flaw about this car is the gauge cluster. If you run out of gas with the needle on a quarter tank that is what it is, not the fuel pump. Test drive this model and try to drive it down to at least the quarter tank. If it dies the dealer is either to fix it or lower the price. Nissan speaks for itself. It even has a low rumble RRRR. The tires are 18/low profile so expect to pay more. People shouldnt compare this to a sports car because its on the same lines as a GS. I owned a 97 Camaro SS. Fast but its a luxury sport. Classy car. People will tell you I have heard of a M but never actually seen one. Very smooth design.

• 

  Value - 2003 Infiniti M45
  By on tilt - October 31 - 6:40 pm

  My brother has owned a G and two Qs and has had great luck with all of them. He took both the Qs to 150K with very little trouble. So I bought the M knowing it had the same great engine of the Q. A great used car value. I picked up an M for 32K and love it. Outer style is okay, but what a superstar to drive. Center console controls are fine once you get to know them. You get great fit-finish, power- handling AND reliability. Typically you dont get all of those benefits in one package. Drive one, youll see. The 06 model looks much nicer, but wont be nearly as soft. If by chance they do get as soft, Ill buy one when this one is worn out.

• 

  Save money, buy lexus - 2006 Infiniti M45
  By CHUCK - October 6 - 11:50 am

  A little harsh ride and quite noisy for a $50k plus vehicle. This clunker has been in the shop almost as many days as its been on the road. "Smart" cruise control shuts off if headed into the sun. Lane departure system beeps when Im in the middle of the lane. Brake cylinder needed to be repaired, door seal deteriorated, AND I ONLY HAVE 7,000 MILES ON IT!!! Looks great but Lexus makes a much better vehicle in the ES330 and GS series and the Lexus ownership experience is far superior (I also have a Lexus SC 430). Dealership treats me like I bought a Yugo. I have already traded this piece of crap after only 6 months on an ES 330.