2011 to 2015 Infiniti M37, M35h, M56 and Q70 / Q70 Hybrid
Infiniti’s flagship sedan packed distinctive looks, attainable pricing, a gorgeously lavish cabin, and no shortage of world-class feature content.
Full-size luxury sedan
Buckle up! With a myriad of models and a mid-cycle nomenclature shift, Infiniti’s flagship model range started life as the M37 and M56, which were later joined by the M35h Hybrid, and was then renamed to Q70. Short- and long-wheelbase versions were available, as were units with rear- or all-wheel drive.
Infiniti’s flagship sedan packed distinctive looks, attainable pricing, a gorgeously lavish cabin, and no shortage of world-class feature content, especially on the safety front. Look for premium Bose audio, sliver-dusted wood trim, climate-controlled memory seats, push-button start, navigation, xenon adaptable headlamps, and plenty more.
With a generous trunk, room to spare for a full complement of adult passengers, and an available Sport package for enhanced handling and braking, combined with three powerplant options, two wheelbases, and a variety of optional equipment, selection on a used M or Q70 should prove plentiful.
At launch, the M37 and M56 offered up a 3.7-litre VQ-series V6, with horsepower in the 330 range, or a 5.6-litre V8 with gobs of torque, and horsepower pushing well past the 400 mark. A seven-speed automatic with available rev-matched paddle shift was standard on all units, and rear- or all-wheel drive could be specified. If you’re after an AWD unit, you’re looking for an M37x or an M56x. Note that an ‘S’ designation in the naming convention referenced the available sport package.
The M35h was the hybrid-powered variant of Nissan’s top-dog sedan, packing a hybridized 3.5-litre V6.
From 2014, all M models were renamed Q70, with newer models offered in both standard Q70 and extended-wheelbase Q70 L (2015 and newer, V8 only) model variants.
What Owners Like
Owners tend to rate performance, styling, feature content, overall value and the lavish cabin most positively, with the punchy stereo system, monstrous V8 torque and all-weather confidence of the AWD system frequently receiving praise. A sense of solid and dense quality throughout the entire vehicle is commonly noted. Rear-seat space in newer extended-wheelbase models borders on excessive.
What Owners Dislike
Common complaints include a few too many warning beepers, a learning curve to some of the high-tech systems, and the lack of on-centre steering feel at speed.
Here’s an owner review, and a few more.
The Test Drive
Complaints reported online seem few and far between, though potential owners of a used copy of Infiniti’s flagship model are advised to make a few checks ahead of their purchase, as well as to have the model inspected by a trained Infiniti technician, for peace of mind.
Sporadically reported are issues with broken door handles, dead batteries, dead radio amps and bad seat motors. These issues are reported very infrequently, though shoppers are advised to check for the proper operation of each of these systems to be safe.
Here’s a useful link to a lengthy owner resource, highlighting common how-to procedures, parts lists, DIY maintenance instructions and more.
Here’s another link to a list of Technical Service Bulletins, or TSB’s, which dealers use to help address common complaints and commonly reported issues. These include a voluntary safety inspection of the transmission case on hybrid powered models, which addresses an infrequently-reported but notable issue with cracking.
A nearly standard bit of warning for modern, high-tech cars, here’s a discussion of the importance of using a trickle charger on your used Infiniti flagship while you’re not driving it. Note that a weak battery charge can cause a plethora of issues ranging from non-functional features to warning messages to random alarm activation.
Surprisingly, a lot of owners seem to customize and modify their Infiniti M / Q70’s. Be on the lookout for out-of-spec camber adjustments, low-quality wheel and suspension upgrades, aftermarket stereo or lighting hardware (which can cause issues with factory wiring and other systems), and especially non-factory engine parts or non-stock engine tuning software, which could damage the engine, or void its warranty. In most cases, shoppers should avoid a model that’s not stock. If the model you’re considering is newer, and has any modifications at all, be sure to have a dealer confirm that the warranty is still valid.
Note that a small handful of owners have reported failure of the timing chain on the 5.6-litre V8 engine, typically under warranty. A high-pitched whine when this engine is revved, while cold, is a telltale warning sign. Remember — this issue is minor compared to the volume of units sold, though worth investigating. More reading here. Note that for many shoppers, the proven 330 horsepower V6 engine will prove powerful enough, not to mention easier on fuel.
If you’re set on a hybrid-powered model, be sure to have an Infiniti dealer inspect the car ahead of purchase, scan all systems, and run the VIN number to see if all software updates, TSB’s and any recalls are up to date. Buying a used hybrid, of any sort, without a full inspection by a dealer-trained technician, is not advised.
A scan of the engine computer for stored trouble codes is a good idea, too. In minutes, a technician can pull any stored warning codes from the computer, which could reveal a bad sensor, or bad part. For instance, Error Code P0305, though relatively rare, indicates a misfire that’s likely caused by one or more bad ignition coil packs, and will require attention.
Here’s a little more reading on the transmission. Any clumsiness, difficulty finding the correct gear, or harsh sensations during gearing up or down can likely be addressed with updated software, though a technician should confirm that this is the case. Transmission damage, or a ‘bad’ transmission, though unlikely, could also cause similar issues.
Like many Infiniti models with the proven 3.7-litre V6, a used M37 or Q70 3.7 looks to be a very solid and reliable used-vehicle purchase, provided it passes all pre-purchase inspections and has been well maintained. A used hybrid, or V8-powered unit can be bought confidently, provided shoppers seek out a mechanical thumbs-up. Extended warranty coverage is a good idea on a hybrid or V8-powered unit, though may amount to overkill with the V6. A well-maintained unit with the 3.7-litre engine will likely be the least expensive to run for the long term.
Crash Test Scores
IIHS: Top Safety Pick+ (2014)
NHTSA: 5/5 Stars (2013)