2012 Infiniti M Hybrid review:

2012 Infiniti M Hybrid

Starting at $53,700
  • Available Engine Hybrid
  • Body style sedan

Roadshow Editors' Rating

8.0 Overall
  • Cabin tech 8
  • Performance tech 8
  • Design 8
Mar 2011

The Good The 2012 Infiniti M35h's next-generation hybrid system generates 360 horsepower and returns fuel economy in the high 20s. Driver assistance systems handle braking in traffic. The cabin tech interface is easy to use.

The Bad Copying contacts from phone to car is a manual process. Trunk space is compromised by the hybrid system battery pack.

The Bottom Line The 2012 Infiniti M35h pushes the envelope with its hybrid system and its driver assistance features, making for one of the most economical luxury sedans, without sacrificing power.


Photo gallery:
2012 Infiniti M Hybrid

Hybrid cars may be high tech, but after hitting an apex in the Toyota Prius and Ford Fusion, the technology stagnated. But now a new generation of hybrid drive system is revitalizing the market. Using lithium ion batteries, these systems operate under electric mode over a greater range of speeds, delivering more efficiency. Such is the case with the 2012 Infiniti M35h, one of the first of the new generation of hybrid vehicle.

The M35h boasts EPA fuel economy of 27 mpg city and 32 mpg highway, an impressive achievement for a luxury sedan that also generates 360 horsepower. The car accelerates quickly, using both the 258 pound-feet of torque from the gas engine and the 199 pound-feet from the electric motor to press you back into the seat when the accelerator is mashed. And this same power train slips into EV mode for long stretches, even when traveling above 60 mph on the freeway.

Infiniti packaged this all-new hybrid power train in its top-of-the-line sedan, the M, a car that has never quite garnered the prestige of executive sedans such as the Mercedes-Benz S-class, the BMW 7-series, or the Lexus LS. The smaller M sedan isn't the kind of car for which you would hire a chauffeur. But it tries to compete with those other cars by offering similar levels of technology, and pushes driver assistance features to an extreme.

The M35h is one among a growing list of luxury hybrids.

Interestingly, the M35h is not alone as an executive-class hybrid. Last year, BMW released its ActiveHybrid 7, and Mercedes-Benz previously launched the S400 hybrid. But of these cars, Infiniti really has the best hybrid system. It not only features idle stop, but it also is able to propel the car under electric power alone, and it gets the best mileage of its competition. It doesn't hurt that the M35h is the cheapest of the lot, either.

Gas and electric power
The M35h relies on Nissan's tried and true VQ-series engine, a 3.5-liter variable valve-timed V-6 as its gasoline-powered component. This engine, though landing on the Ward's 10 best engines list repeatedly over the years, is not very advanced by current standards, and was even knocked off Ward's 2011 list by Nissan's own electric motor powering the Leaf.

The trunk space is shallow because of the battery pack, but Infiniti says it still fits four golf bags.

However, the research Nissan did for the Leaf also paid off for the Infiniti M35h, as both cars use lithium ion battery packs. The M35h gets a 50-kilowatt pack mounted just behind the rear seats, compromising the trunk space. This battery powers a 67-horsepower electric motor capable of driving the car. A regenerative braking system, similar to that used in most hybrids, charges up the battery. Although this is a new-generation hybrid, there is no plug-in capability.

A gentle touch on the accelerator makes the car move forward in EV mode, indicated by a green light on the tachometer. With that same gentle push, the car will continue to accelerate under electric power, the engine remaining off. But so as not to cause a traffic jam and also to get the most out of the car, it works better to push off harder, spooling the engine up to cruising speed, after which it will shut down, only coming on as needed.

Switching the dial to Sport mode affects the throttle and transmission.

To maximize EV time, the car features an Eco mode, accessible with a dial on the console. Eco mode detunes throttle response to a sometimes frustrating degree. Forget about any sort of satisfying acceleration, the M35h will barely get out of its own way.

But the console dial has two other modes, Snow and Sport. Snow reduces torque to the wheels, and is meant to keep the car from losing traction on slippery roads. Sport mode generally keeps the engine speed above 3,000rpm, making for ready power. But even in Sport mode the car will switch to electric drive when conditions call for it.

Sport mode also affects the transmission, which explains why there is no separate sport setting on the shifter. With its seven gears, this automatic transmission helps the car's fuel economy mission. A manual mode lets the driver shift through the gears sequentially, and allows more aggressive driving than the Sport mode.

This animation shows the mix of power from the battery and engine.

Further putting the M35h in the efficient luxury camp more than sport luxury is the suspension, which is sprung soft. Infiniti also doesn't take the M35h's tech so far as to offer an active suspension. Sway bars keep the car reasonably stable under hard cornering, but as a fixed suspension, Infiniti had to find a compromise setting between rigid and soft.

Infiniti fits the M35h with an electrohydraulic power-steering unit, essential for times when the engine shuts down. At speed, it is difficult to tell that it is not a conventional hydraulic power-steering unit, attesting to Infiniti's tuning job. But it is also not exceedingly sharp, showing the kind of understeer present on average cars. Again, the M35h is more luxury than sport.

Almost drives itself
The climate control system in the M35h is also unaffected by engine shutdown, so it must rely on electric components. Climate control offers Infiniti's Forest Air feature, which causes air flow from the vents to fluctuate, the idea being to simulate a natural breeze. It is a subtle effect, and can be turned off with a button on the dashboard.

The car delivered to CNET came with the Technology package, bundling Infiniti's innovative driver assistance features. This package includes typical technologies, such as blind-spot detection and adaptive cruise control, as well as the more far-reaching Distance Control Assist.

These buttons turn on adaptive cruise control and the automatic braking function.

This latter technology, turned off by default, hits the brakes, bringing the car to a stop when it approaches stopped traffic. You can actually rely on it to do your braking for you. The only drawback in city traffic is that it stops about a car length behind other cars. It also only holds the brakes down for a brief time, letting the car creep forward after the initial stop.

Blind-spot detection activates lights in the A pillars when other cars are in the lanes next to the M35h, and causes those lights to blink if the turn signal activates. Adaptive cruise control works like competitive systems, slowing the car down from its set speed to match the pace of slower traffic ahead. It has three following distances and can bring the M35h to a full stop if traffic ahead stops.

Add to these features Infiniti's lane departure warning and prevention technologies, and the M35h can almost drive itself.

Fast maps
Cabin tech in the M35h doesn't take the same leap forward as the power train. Instead, the car comes with the same navigation system Infiniti has used for some time. With maps stored on a hard drive, the system works quickly, and even shows some 3D building renderings, but the look of the maps is a little sloppy, far from the sophisticated offerings of BMW and Audi.

The navigation system shows some 3D features, but these maps are not as refined as those from BMW and Audi.

For its latest M sedan, Infiniti did, however, make the interface controller a little nicer. Instead of the knob crowned by directional buttons of previous years, Infiniti has gone to a combo joystick dial, which has a look in keeping with the car's luxury mission. And it still offers the same excellent interface from previous models, making it easy to choose items from a list or navigate an onscreen keyboard.

The stereo system comes from Bose, and has 16 speakers, including four small speakers in the shoulders of the front seats. This system is very well balanced, producing a strong, solid sound. It can deliver striking bass or delicate treble notes equally well. It really stood out for vocals, conveying rich tones.

Audio sources are complete, with everything from Bluetooth streaming to the onboard hard drive to Satellite Radio. Selecting music from a connected iPod was easy through the cabin tech interface, which showed good responsiveness. However, with a USB drive plugged into the system, it did not want to look into folders, seeming to want all the music files in the root directory.

With the Favorite Artists feature, the car will let you know when certain artists are playing on any satellite radio station.

The car's satellite radio has a new feature called Favorite artists and songs. Program in a particular artist or track, and the car lets you know when any of the satellite radio stations starts playing it.

Infiniti's Bluetooth phone system has been a weak spot in its cars, not offering the same sort of automatic contact list download as the competition. That issue is addressed, although not entirely fixed, in the M35h. The phone system does not grab an entire contact list from a paired phone, but it does let you copy over contacts one at a time, which can be a tedious process. Once the contact is stored in the car, you can say the name of a person to have the voice command system initiate a call.

In sum
The 2012 Infiniti M35h scores high points for its hybrid power system, one of the best available. Its transmission and steering also rate high on the tech meter, but its suspension remains conventional.

As for design, Infiniti offers one of the best cabin tech interfaces around, attractive and very usable. Attractive exterior styling also works in the car's favor, setting it apart from more staid-looking sedans. The battery pack eats into the car's practicality, as it takes up considerable trunk space.

Cabin tech features are solid in the M35h, but here it falls short of luxury competitors. The stereo system is the most advanced feature, offering many audio sources and well-balanced sound. Navigation works well, but only integrates traffic and weather for external data sources. The phone system is the weakest feature of the M35h, as its ability to download a paired phone's contact list is limited.

Tech specs
Model2012 Infiniti M35h
Trimn/a
Power train3.5-liter V-6, seven-speed automatic transmission, 50-kilowatt lithium ion hybrid power system
EPA fuel economy27 mpg city/32 mpg highway
Observed fuel economy24.6 mpg
NavigationOptional hard-drive-based with traffic
Bluetooth phone supportStandard
Disc playerMP3-compatible single CD
MP3 player supportiPod integration
Other digital audioOnboard hard drive, Bluetooth audio streaming, USB drive, satellite radio
Audio systemBose 16-speaker surround sound system
Driver aidsRearview camera, blind-spot detection, lane departure warning, lane departure prevention, adaptive cruise control, distance control
Base price$53,700
Price as tested$64,725

This week on Roadshow

Discuss 2012 Infiniti M Hybrid