Infiniti M45 Review

2009 Infiniti M45 Sport Sedan Shown

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 it launched the V8-powered, rear-wheel-drive M45. 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 current Infiniti M45, however, has enjoyed wide critical acclaim. With substantially more space, a tremendous amount of technology and comfort features, and a bold, imposing exterior design, today's M45 is a high-tech powerhouse with plenty to offer midsize luxury car shoppers. Its performance capabilities have been raised significantly due to things like available four-wheel steering, a precisely tuned suspension and strong brakes. Even though the V6-powered M35 represents a significantly better value, the current M45 is a swift, stylish, superbly executed luxury sedan that should be considered with the top players in the segment.

Current Infiniti M45

Today's Infiniti M45 luxury sedan comes in two trim levels -- M45 and M45x AWD -- although both are pretty evenly equipped, save for the latter's all-wheel-drive system. They offer most of the luxury niceties you'd expect in this price range (leather upholstery, heated and cooled seats, Bluetooth), while option packages add things like navigation, a console-mounted DVD player, adaptive cruise control, reclining/heated rear seats and 14-speaker Bose surround-sound audio. A Sport package adds rear active steering, a sport-tuned suspension, 19-inch wheels, high-performance tires, a sport steering wheel and different interior trim and seats.

All M45 models are motivated by a powerful 4.5-liter V8 that sends 325 horsepower and 336 pound-feet of torque to either the rear wheels or all four (M45x AWD). The M45's five-speed automatic transmission has manual shift control and a sporty rev-matching feature that imparts a particularly lively feel to downshifts. Infiniti also offers a 303-hp, V6-powered version of the sedan called the M35.

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

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

Used Infiniti M45 Models

The current generation Infiniti M45 dates back to 2006. First-year models are listed as having more power than subsequent models, but this is due to a change in horsepower measurement rather than actual output. Changes were restricted to feature additions in its second year. 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.

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 stealth speed and luxury, and don't need a lot in the way of interior room, the previous-generation Infiniti M45 could be a good match.

SELECT A SPECIFIC INFINITI M45 MODEL YEAR*

* Edmunds.com maintains vehicle data as far back as 1990.