2007 Infiniti M56 - Wrap-Up

2011 Infiniti M56 Long-Term Test

  • Full Review
  • Pricing & Specs
  • Road Tests (3)
  • Comparison (1)
  • Long-Term

Read the introduction of this vehicle to our long-term fleet.

See all of the blog posts on the 2011 Infiniti M56.

When Infiniti offered us a 2011 M56 for a long-term test, we accepted on one condition — it had to be a standard model, no Sport package allowed.

We had tested Infiniti's newly redesigned flagship sedan twice before (M56 vs. Mercedes-Benz E550 and M56 vs. BMW 550i). Both Ms tested were the M56S, with the Sport package, and both rode like covered wagons. No thanks. We liked the car, but the rough ride was a deal-breaker. And a back-breaker.

Infiniti agreed and sent us a tech-laden silver M56 with no Sport package. The timing was perfect. We were just weeks away from introducing a long-term 2011 BMW 528i and 2011 Hyundai Equus to the fleet. The next 12 months and 20,000 miles offered an ideal opportunity for direct comparison of the three luxury sedans.

Power Delivery
One attribute of the 2011 Infiniti M56 that first attracted us rested beneath the hood. Its 5.6-liter V8 generates 420 horsepower and 417 pound-feet of torque. Power is sent to the rear wheels via its seven-speed automatic transmission and delivered with the wiggle of a toe.

Engineering Editor Jason Kavanagh was at the helm when we strapped our M56 to the inertia dyno. Kavanagh blogged, "There's more than 350 lb-ft of torque to the wheels between 2,400 and 5,400 rpm and a peak of 377 lb-ft. For a luxury car to properly soothe, you don't want some cammy, thumping beast of an engine. Those are great for sporting vehicles but just don't cut it in a luxosedan. You do, however, want torque. Preferably down low, to help a heavy sedan of the line. This XK56VD, as it's known internally, is no slouch down low."

As with so many vehicles today, electronic throttle sensitivity created a divide within our ranks. Some priced out aftermarket throttle cables and urged Infiniti to revert to the good old days. Others found peace with the electrons. Editor Ed Hellwig explained, "No doubt, the Sport setting is worth it. I know we panned the M56 for being too sporty when it went up against the BMW in a recent comparison test. But this setting is different as it applies to the throttle and transmission settings only. Here, Infiniti got it right. The throttle is more aggressive for sure, but it's not too jumpy. It doesn't make the car twitch every time you adjust your right foot. Instead, it just feeds out its substantial power in a more urgent manner."

Features and More Features
Horsepower was not the only appeal of the 2011 Infiniti M56. Inside the cabin we optioned up the Infiniti. Our test car wore $8,500 worth of extra equipment. A 16-speaker Bose surround-sound system tickled our ears. White ash wood trim, contrast piping and quilted seat patterns pleased our eyes. And our nose welcomed creatively named ventilation system components like Forest Air, Breeze Mode, Plasmacluster purifiers and Grape Polyphenol filters. Infiniti made every attempt to create a serene atmosphere in the M.

Driver assist features added further peace of mind. "I've got the cruise set to 74 mph," began one editor, "and the car is only going 10 mph. That's because the M's Intelligent Cruise Control will slow the car to a complete stop in traffic. It's an amazing technology."

Intelligent brake assist (IBA) was another aid, which senses obstacles and applies brakes at the last minute to minimize front impacts. We found the IBA light on occasionally. Senior Editor Josh Jacquot explained, "There are two and a half pages of the owner's manual dedicated to the IBA system, why it might fail and what might cause the failure. Whatever. Could be a dozen reasons why, none of which seem to matter since it turned off immediately. The car is still awesome." Blind spot warnings, lane departure warnings and pre-crash seatbelt tensioners rounded out the list of driver aids available within the $3,000 Technology package.

Still, the M's laundry list of tech proved easy to use over our 12 months with the car. Deep dives into the owner's manual were rare and user frustration was not a factor.

Send It on a Road Trip
There was one way to isolate the 2011 Infiniti M56 and test its features, performance and ride quality on a single stage. Send it on a road trip. So in addition to adding thousands of miles to the odometer around town, we added thousands more on extended trips.

Kavanagh wrote, "This past weekend was my first time in the big sedan, and the car in this guise is far more convincing than in full-kill Sport trim. I came away from my time with the Sport thinking it was trying too hard?too much trying to convince you that it's a real sport sedan. It wasn't honest. When the M56 is dialed back a notch as it is with this long-termer, it's a terrific car. It has the compliance you want but still enough substance in the damping and steering to convey a premium vibe. Shades of sportiness without all the pretense. It's honest."

We universally agreed with this assessment of the ride quality and its superiority over the sportier M56S. Yet its refinement was still not up to the levels of the comparable BMW and Mercedes-Benz sedans we've referenced. Was this a bad thing? Certainly not. This M56 seemed to want performance accolades first and luxury second.

Interior Reflections
After 20,000 miles we knew the M56 inside and out. As one editor said, "Infiniti really designed this interior nicely. There is a cohesive flow between leather pieces, wood accents and switchgear that is not only attractive, but ergonomically thoughtful. The controls are simple and right where they need to be."

We agreed the layout was tastefully done, but some felt the use of chrome was one glaring mistake on Infiniti's part. "Chrome doesn't belong in interiors," one rant started. "Especially on surfaces as close to the driver as the face of the steering wheel. On certain stretches of road it is absolutely blinding and hits me right in the eyes."

For other editors the brightwork was easy on the eyes and gave the M56 a rich ambience.

Beyond its design elements, the 2011 Infiniti M56 interior satisfied all other needs of practicality. All seating positions were comfortable, though some felt the driver seat did not adjust low enough. Rear passengers had adequate leg- and headroom. And the trunk cargo area was immense. If we had a request for the next-gen M56, it would be for a folding rear seatback. The cargo pass-through isn't always enough.

Maintenance and Warranty Repairs
Our M56 held steady on the maintenance front. Santa Monica Infiniti, within 2 miles of our office, addressed all service needs. We also had a history of decent service quality, so there was no reason to look elsewhere. Service at 7,500 and 15,000 miles was straightforward and averaged $80 for basic upkeep. But there was more.

Between routine services we encountered some issues. At 11,000 miles a stone struck the windshield and grew quickly from star to crack, requiring replacement. Aftermarket glass was unavailable, so we paid $1,300 for a new windshield. Along the way the dealer also performed a navigation software update and replaced a faulty Bluetooth microphone, both under warranty. At 12,000 miles our M56 spawned the trunk monkey.

Senior Editor Josh Jacquot recounted, "So I jumped in the M56 for my early commute this morning, threw it in reverse and was immediately alerted to the presence of a trunk monkey." Essentially, the rear sunshade failed. Any attempt to retract it was met with an obnoxious jackhammering from the rear seat shelf. Keep in mind that every time the car shifts to reverse it automatically retracts the shade for safety reasons. So the noise was frequent and it was loud. We saw the dealer promptly for the warranty repair, though we had to wait a day for parts.

12 Months Behind Us
We spent 12 months and 20,000 miles with the 2011 Infiniti M56. And we loved it. And we were glad we didn't order the Sport package. Without it our long-term M56 rode considerably better, yet it remained a true sport sedan. No, it isn't perfect, but its wonderful interior and 420-hp V8 make it easy to forgive some of its shortcomings.

Amenities also left an impression on us. We appreciated the long list of optional comfort features in the M56. The driver assist technologies were impressive and the sedan's in-cabin electronics were easy to use.

When it was time to retire the M56 from service, Edmunds' TMV® Calculator valued the sedan at $50,036. This figure is based on a private-party sale. It is also equivalent to 26 percent depreciation from the original MSRP. Under similar circumstances our long-term BMW 528i depreciated 22 percent.

We spent minimal time and money to keep the 2011 Infiniti M56 on the road. Routine service was affordable. The windshield replacement was not; however, it was also not the car's fault. Overall, it was a positive ownership experience. We will miss having the M56 around.

Total Body Repair Costs: None
Total Routine Maintenance Costs: $171.65 (over 12 months)
Additional Maintenance Costs: $1,300.64
Warranty Repairs: Replace rear sunshade, replace Bluetooth microphone, update navigation software
Non-Warranty Repairs: None
Scheduled Dealer Visits: 2
Unscheduled Dealer Visits: 2
Days Out of Service: 4
Breakdowns Stranding Driver: None
Best Fuel Economy: 26.4 mpg
Worst Fuel Economy: 10.8 mpg
Average Fuel Economy: 18.8 mpg
True Market Value at service end: $50,036 (private-party sale)
Depreciation: $17,189 (or 26% of original MSRP)
Final Odometer Reading: 20,371 miles

The manufacturer provided Edmunds this vehicle for the purposes of evaluation.

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