Infiniti M Review

When it comes to buying a luxury sedan, most people usually stick with one of the ubiquitous models offered by traditional European luxury brands. But if you're someone who likes to look beyond the obvious choices, you'd be wise to add the Infiniti M to your short list.

That's because this midsize luxury sedan has matched, and in some ways bested, those traditional sport sedans from BMW and Mercedes-Benz at their own game. With strong engines, an attractive passenger cabin lined with top-quality materials, and a features list full of the latest cutting-edge gadgets, the M gives you a lot of bang for your buck.

Note that for 2014 this model's name was changed to Infiniti Q70. It is covered in a separate review.

Used Infiniti M Models
The last, fourth-generation Infiniti M was produced from 2011 through 2013. Initially, there were two versions of this midsize luxury sedan -- the M37 with a 3.7-liter, 330-horsepower V6 and the M56 with a 5.6-liter, 420-hp V8. The M35h arrived for 2012, sporting a hybrid powertrain with a combined 360 hp from its gas-fueled 3.5-liter V6 and electric motor. Rear-wheel drive was standard, but models with an "x" indicate the presence of all-wheel drive. The sole transmission was a seven-speed automatic with four different shift modes: Normal, Sport, Snow or Eco. There were no notable changes throughout this generation's run.

All M models came standard with automatic xenon lights, a sunroof, keyless ignition/entry, leather upholstery, heated power seats, a power tilt-and-telescoping steering wheel, a rearview camera, Bluetooth and an iPod interface. The M56 added rear parking sensors, a navigation system, ventilated front seats and an upgraded audio system with digital music storage, but these were optional on the M37 and M35h.

Option highlights for all M sedans included a power rear sunshade, an air purifier, upgraded leather upholstery, a 16-speaker Bose audio system, adaptive cruise control and numerous electronic accident avoidance systems.

While the Infiniti M boasts a handsome exterior, it gets even better when you hop inside. Stylish design accented with supple leather and genuine wood set the mood. Seating is comfortable up front, and the rear seat offers ample room. The electronics interface is one of the most user-friendly of any luxury car.

In reviews, we found that the M37 and the M56 both drive smaller than they look, with sharp reflexes through corners and quick acceleration. The optional Sport package took it a step further with 20-inch wheels, summer tires, a sport-tuned suspension, four-wheel active steering (rear-drive models only) and sport seats. Unfortunately, the firmer ride associated with this package is just too rough for a segment noted for its refinement and comfort. Also, the transmission can occasionally suffer from inconsistent shift timing. The hybrid is simply impressive, as it matches the M56's incredible acceleration while beating the M37's combined fuel economy by 8 mpg.

Overall, however, the M still lacks the utter refinement that makes rivals from BMW, Jaguar and Mercedes-Benz so compelling. But for many, the more attractive pricing and typically much lower ownership cost of a used M37 or M56 will make this Infiniti a compelling choice. Furthermore, the M35h's incredible combination of power and fuel economy is impossible to ignore, and as such, eco-minded luxury buyers would be keen to put it at the top of their shopping list.

The previous, third-generation M was produced from 2006-'10 in M35 and M45 models. Compared to its successor, it was more angular in appearance and thus not as visually interesting inside and out. Obviously, there are countless mechanical differences from one generation to the next, but many of the same attributes that make the most recent M appealing also apply to this generation, with strong performance, excellent handling and high feature content being among them.

Originally, the M35's 3.5-liter V6 produced 280 hp and was mated to a five-speed automatic. For 2009, power output was increased to 303 hp and a new seven-speed automatic was introduced for rear-wheel-drive models only. The all-wheel-drive M35x always featured the five-speed.

The M45 featured a 4.5-liter V8 listed as 335 hp in its first year, but 325 hp thereafter due to a change in the way horsepower was measured (actual output did not change). A five-speed automatic was the only transmission available and all-wheel drive was not available prior to '08.

Regardless of which engine you chose, this Infiniti M provided plenty of power. Braking was also impressive, and a firmly damped suspension delivered finely controlled balance through corners. The trade-off was a suspension that tended to transmit road irregularities into the cabin, and at highway speeds, a noticeable amount of noise. While these flaws certainly didn't make the M uncomfortable, it was somewhat less peaceful than other performance luxury cruisers.

We had similar mixed feelings about the interior. It was attractive, amply equipped 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 M 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've been.

In total, this generation of Infiniti M was very much like the one that came after, albeit with less style and performance. It was never quite up to the level of its European competitors, but then it had a strong value proposition that carried over to the used market. Should you be interested in finding one, keep in mind that changes were relatively minor, with 2008 being the only year of significant non-engine alterations. Styling was tweaked, the navigation system was upgraded and new high-tech features like adaptive cruise control and lane-departure warning were added.

The second-generation Infiniti M was sold only as the M45 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 the succeeding 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.

The original M was one of Infiniti's two original models. Dubbed M30 and sold from 1990-'92, it was powered by a V6 and available in coupe and convertible body styles.

Read the most recent 2013 Infiniti M review.

If you are looking for older years, visit our used Infiniti M page.