2011 BMW 550i vs. 2011 Infiniti M56 Comparison Test

2011 Infiniti M56 Sedan

(5.6L V8 7-speed Automatic)
  • 2011 Infiniti M56 vs. 2011 BMW 550i Comparison Test

    Inside Line puts the 2011 BMW 550i and the 2011 Infiniti M56 in a head to head comparison test of performance luxury sedans. | December 27, 2010

1 Video , 58 Photos

  • Comparison Test
  • Top 7 Features
  • Editors' Evaluations
  • Data and Charts
  • Final Rankings and Scoring Explanation
  • 2011 BMW 5 Series 550i Specs and Performance
  • 2011 Infiniti M56 Specs and Performance

When it comes to respectability in the midsize sport sedan segment, all roads lead through BMW's 5 Series. It's been ruling this class for decades now, and for good reason. It has the uncanny ability to satisfy both driving enthusiasts and buyers who are simply looking for a luxury sedan with German cachet.

Now that the all-new twin-turbo 2011 BMW 550i is here, it was time to see just how well it stacks up against its newest competitors. But instead of going toe-to-toe with a classic European rival, we figured a match-up with the latest from Japan would be more interesting. For that we turned to the all-new 2011 Infiniti M56, a thoroughly redesigned sedan that is once again aiming for the Germans. It has all the makings of a worthy competitor, but how does it hold up on the road?

How They Stack Up
Not surprisingly, the 2011 BMW 550i and 2011 Infiniti M56 have plenty of similarities. Both are rear-drive sedans powered by sizable V8s. In this case, both are hooked to automatic transmissions, a seven-speed in the Infiniti and an eight-speed in the BMW.

To make sure no one whines about "stacking the deck" in one car's favor, both the 550i and the M56 were outfitted with Sport packages. The Infiniti's $3,650 option adds a stiffer suspension with upgraded springs and shocks, larger brakes, Bridgestone Potenza RE050A summer performance tires on 20-inch alloy wheels, four-wheel active steer, paddle shifters, sport seats and a unique steering wheel and shift knob.

2011 BMW 550i vs. 2011 Infiniti M56

The BMW 550i had the benefit of both a Dynamic Handling package, which includes electronic damping control, active roll stabilization (active antiroll bars) and Adaptive Drive (allowing for specific chassis/drivetrain settings) for $2,700, as well as a $2,200 Sport package, which adds a sportier leather steering wheel, multicontour seats, special exterior trim, an increased top speed (limited to 150 mph) and — surprisingly — 19-inch Goodyear Excellence run-flat all-season tires.

Technology and luxury abound in these cars, the kind of niceties that make your drive safer (the BMW's standard adaptive cornering headlights) and more relaxing (Infiniti's standard heated and cooled front seats). Differences come in the form of which features each manufacturer supplies standard, and which ones they make you pay extra for — as an example, you can get those adaptive headlights on the Infiniti, but it'll cost $3,000 as part of the Technology package; conversely, neither heated nor cooled front seats come standard in the BMW — heated seats cost $500 (or could be part of a package), while seat cooling tacks on another $1,950-$2,950 depending on the package.

As you might have guessed, these are expensive sedans. The M56 starts at $58,765 with an as-tested price of $67,130, while the BMW is a few grand more. The 550i starts at $60,575 and our tester topped $70K with options.

What's the Motivation Here?
Turbocharged engines are quickly becoming the norm at BMW, and now the 550i is on board. Its direct-injected 4.4-liter twin-turbo V8 produces 400 horsepower at 5,500 rpm and 450 pound-feet of torque from 1,750-4,500 rpm. Yes, that's a massive torque curve, but it comes at the expense of the old V8's rumbling exhaust. Now there's little more than a muted growl, and you can't even hear the turbos working their magic.

The 2011 Infiniti M56 uses cubic inches and plenty of revs to achieve its power. Its 5.6-liter V8 is good for 420 hp at 6,000 rpm and 417 lb-ft of torque at 4,400. It's no dinosaur, also utilizing direct-injection and variable valve timing and valve lift for a smooth, reasonably efficient power plant.

A little more driver involvement is required to get the most out of the M56's V8, though, as its power is concentrated at higher engine speeds. The Infiniti sounds more like a sport sedan than the BMW, especially when it approaches the 6,700-rpm redline.

By the Numbers
At our test track, the M56 was slightly quicker to 60 mph than the 550i, 5.0 to 5.2 seconds, respectively (4.7 and 4.9 seconds with a 1-foot rollout, as on a drag strip). So the BMW is slower, despite the fact that it's capable of getting a near-perfect amount of wheelspin off the line thanks to power-braking, something the Infiniti's brake-override system won't allow.

So how come the BMW is slower? Might have something to do with the extra 287 pounds of ballast the 4,380-pound 550i carries versus the M56. Seriously, what's a 5 Series doing weighing nearly 4,400 pounds? This is "EfficientDynamics?"

2011 BMW 550i vs. 2011 Infiniti M56

Weight aside, by the time the 550i hits the quarter-mile, its twin-turbo V8 inches the BMW ahead by 0.1 second (13.2 vs. 13.3); it's also traveling a lot faster at this point — 108.3 mph against the Infiniti's 106.7.

A Shifty Pair
The BMW 550i comes standard with a six-speed manual transmission, but our test car was fitted with the no-cost-option eight-speed automatic. BMW says this new tranny's two additional ratios (over the old six-speed auto) come with no increase in size or weight.

It's a smooth operator in full automatic mode and easy to shift when you want to take control of the gears yourself. Not only does it shift in our preferred pattern (forward for downshifts, back for upshifts), it also blips the throttle when you grab a lower gear to match revs. It's not actually a true full manual mode, though, as a stomp on the gas will call up a multigear downshift. It doesn't hold gears either. If you hit the redline, you get the next cog whether you like it or not.

Infiniti offers just one transmission in the M56, a seven-speed automatic with four driver-controlled modes that affect transmission and throttle mappings. As with the BMW, leaving the center console shifter in "D" gives supremely smooth automatic shifting. But moving the center console lever toward the driver puts it in Manual mode, bringing the optional leather-covered, steering-column-mounted magnesium paddle shifters into play. The control is fully with the driver at this point, as the transmission will neither shift up nor down without consent from the paddle shifters. Downshift under braking and it rev matches, too.

These Are Sport Sedans, After All
With all of the BMW's high-techery, you'd think it would easily handle the Infiniti when the going gets twisty. Not so, especially in terms of instrumented testing. The M56 bested the 550i by 1.2 mph through the slalom (66.7 vs. 65.5 mph, respectively) while generating 0.89g around the skid pad against the BMW's so-so 0.84g.

The blame for the 550i's less-than-stellar performance doesn't lie purely with its all-season tires either, as they provided enough grip for it to stop almost as well as the M56 — just 1 foot longer from both 30 and 60 mph. The BMW's pedal felt stronger at the test track, but when pushing hard on back roads the Infiniti's optional ($370) high-friction brake pads felt more consistent.

2011 BMW 550i vs. 2011 Infiniti M56

More than anything, the 550i is simply too heavy and softly sprung for aggressive back-road driving. Even with the suspension at its stiffest setting, the 550i exhibited a surprising amount of understeer, while the 5's electric power steering feels artificial. You can still flog the 550i, but you won't feel completely in touch with the car.

The Infiniti isn't spot-on either. Its variable-assist steering, combined with the optional four-wheel active steering (the rear wheels are turned in phase with the front wheels, depending on vehicle speed and steering angle), makes for overly quick turn-in at low to medium speeds, alarmingly so at times.

But it's clear the driver seat of the Infiniti is the place to be when you pick up the pace on any kind of curvy road. The M56's steering becomes more and more natural as speeds increase, while the stiff suspension soaks up turns, if not bumps, with ease. The whole M56 experience, from its quick steering to its stiff suspension, is a bit on the frenetic side, but it's more engaging than the vague BMW.

There is one area where the BMW trumps the Infiniti on the fun scale — powerslides. Now, the average enthusiast may not find this very relevant, but in the right hands the BMW's electronic limited-slip rear differential does allows you to utilize the twin-turbo V8's prodigious low-end torque to induce some wicked corner exits. And that's all we'll say about that.

When You're Not Laying Rubber
Our enthusiasm for the Infiniti drops slightly the moment the road gets bumpy, or basically any time you're just driving from A to B. The M56's stiff, nonadjustable suspension makes the average commute tiresome and unnecessarily jumpy. The tire and road noise is also a bit much for a luxury sedan, too. Basically, this car reminds you that you bought the Sport package every time you drive it.

The BMW, on the other hand, is always plush and serene. The same sedan that can execute tire-smoking powerslides can also tame mangled city streets. We would still prefer more steering feedback, but the trade-off is slightly less sawing at the wheel during normal driving. It's still a sport sedan, but one you can live with.

No Cabin Fever Here
When you pay around $70,000 for a luxury sport sedan, you expect to be coddled, and neither car disappoints. Both are extremely comfortable places to spend time, the BMW's front seats getting the nod for their width and comfort, the Infiniti's for lateral support.

The M56's rear seat is more plush, while the BMW has more headroom. Fine leather and wood abound, as do such niceties as power rear window shades and excellent navigation systems, the BMW in particular boasting an impressive 10.2-inch transreflective screen that becomes easier to see in direct sunlight — the exact opposite of many systems.

In general the BMW's controls have better detents and are more ergonomic, while the Infiniti's are easier to decipher from the moment you sit in the car. And yes, iDrive Version 4 can still be a bit nonintuitive.

2011 BMW 550i vs. 2011 Infiniti M56

When it comes to interior design, though, the Infiniti has a more interesting take on luxury. The mix of materials in the M56 is more modern and stylish without looking overdone. The 550i has plenty of high-quality stuff; it's just on the sterile side.

And the Winner Is...
As athletic and well-mannered as the Infiniti is on back roads, the BMW 550i squeezed out a win by 2.2 points. Why?

The BMW 550i is simply a better all-around sedan. Infiniti may have figured out the sport sedan piece of the formula, but BMW is better at making a sport sedan that you can live with. We like a tightly wound sedan as much as the next enthusiast, but we don't want to be reminded of the car's capabilities every time we head to the office. It's a fine line for sure, but one the Infiniti still needs to work on.

With the 550i, you get the refined driving experience along with plenty of sport sedan capability. Should it weigh less? Yes. Would we prefer more precise steering? Yes again. The new 5 Series is by no means perfect, but it still puts all the pieces together in a way that makes it feel like a proper luxury sport sedan. The Infiniti is close, but the BMW is already there.

The manufacturers provided Edmunds these vehicles for the purposes of evaluation.

You'd think any luxury/sport sedan starting at around $60,000 would come with a plethora of the latest features to both coddle you and make your driving experience more fun. But as the list below shows, BMW and Infiniti have widely differing views on what should come standard and what the customer should have to cough up extra coin for. A critical miscue by Infiniti is the lack of a limited-slip differential, even as an option. Here's our list of features that we think a sport sedan in this category should have.

Features
  BMW 550i Infiniti M56
Adaptive cornering headlights S O*
Adaptive suspension damping O N/A
Cooled front seats O* S
Heated front seats O S
Limited-slip differential S N/A
Paddle shifters O* O
Rear-wheel steering O* O


Key:
S: Standard
O: Optional
N/A: Not Available

Adaptive cornering headlights: Anyone who drives on curvy roads at night will find much joy in "cornering" headlights, which are standard equipment on the BMW 550i. BMW's system decides how much the lights, which look through the turns, should move based on steering, yaw rate and vehicle speed.

Adaptive suspension damping: The 550i's optional Driving Dynamics Control lets the driver choose among four different settings for its electromagnetic shocks, allowing you to cruise comfortably on the highway, or stiffen things up for back-road duty. Adjustable suspension isn't even optional on the Infiniti.

Cooled front seats: No one likes showing up to a meeting with a sweaty backside on a stifling hot summer day. Luckily, more and more carmakers have been making seat cooling available — better yet, it's standard equipment on the M56.

Heated front seats: "Bun warmers" have become pretty much standard fare on luxury cars these days. Yet BMW still makes you pay for that toasty feeling in its 5 Series.

Limited-slip differential: There's nothing quite like powering out of a turn, only to have the inside rear wheel spin uselessly, as on the Infiniti. The BMW 550i's electronic limited-slip diff simulates a traditional mechanical diff by adding brakes individually to the rear wheels — only when DSC is deactivated.

Paddle shifters: Paddle shifters bring some of the driver interaction lost through an automatic transmission back to the driver. They're optional on both cars, but only the Infiniti was equipped as such for this test — nice, big steering-column-mounted, leather-covered magnesium versions.

Rear-wheel steering: Infiniti's four-wheel active steer comes with the M56's $3,650 Sport package, and it's part of the reason the M56 has such crazy-quick turn-in at low-to-medium speeds. But that ultra-quick steering can also be a bit disconcerting and unnatural-feeling, so this is an acquired taste.

Evaluation - Drive
Evaluation - Ride
Evaluation - Design
Evaluation - Function

Evaluation - Drive

Overall Dynamics
Vehicle Score Rank
BMW 550i 7.5 2
Infiniti M56 7.5 1

Engine Performance
Vehicle Score Rank
BMW 550i 8.0 1
Infiniti M56 8.0 1

Transmission Performance
Vehicle Score Rank
BMW 550i 8.0 1
Infiniti M56 7.5 2

Brake Performance
Vehicle Score Rank
BMW 550i 7.0 2
Infiniti M56 8.0 1

Steering Performance
Vehicle Score Rank
BMW 550i 7.3 1
Infiniti M56 6.3 2

Handling
Vehicle Score Rank
BMW 550i 7.5 1
Infiniti M56 7.5 1

Fun to Drive
Vehicle Score Rank
BMW 550i 7.0 2
Infiniti M56 7.5 1

Evaluation - Ride

Overall Comfort
Vehicle Score Rank
BMW 550i 8.2 1
Infiniti M56 7.3 2

Ride Comfort
Vehicle Score Rank
BMW 550i 8.8 1
Infiniti M56 6.3 2

Wind Noise
Vehicle Score Rank
BMW 550i 8.0 1
Infiniti M56 8.0 1

Road Noise
Vehicle Score Rank
BMW 550i 8.0 1
Infiniti M56 6.3 2

Front Seat Comfort/Space/Access
Vehicle Score Rank
BMW 550i 8.8 1
Infiniti M56 7.5 2

Rear Seat Comfort/Space/Access
Vehicle Score Rank
BMW 550i 7.5 2
Infiniti M56 8.0 1

Driving Position
Vehicle Score Rank
BMW 550i 8.0 1
Infiniti M56 7.5 2

Evaluation - Design

Overall Design & Build Quality
Vehicle Score Rank
BMW 550i 7.7 1
Infiniti M56 7.4 2

Exterior Design
Vehicle Score Rank
BMW 550i 7.8 1
Infiniti M56 7.0 2

Interior Design
Vehicle Score Rank
BMW 550i 7.5 2
Infiniti M56 8.0 1

Interior Materials
Vehicle Score Rank
BMW 550i 7.5 2
Infiniti M56 8.0 1

Interior Control Tactile Feel
Vehicle Score Rank
BMW 550i 8.3 1
Infiniti M56 7.0 2

Squeaks & Rattles
Vehicle Score Rank
BMW 550i 7.5 1
Infiniti M56 7.0 2

Panel Fitment & Gaps
Vehicle Score Rank
BMW 550i 7.5 1
Infiniti M56 7.5 1


Evaluation - Function

Overall Function
Vehicle Score Rank
BMW 550i 7.6 1
Infiniti M56 7.3 2

Headlamp Illumination
Vehicle Score Rank
BMW 550i 9.0 1
Infiniti M56 8.0 2

Visibility
Vehicle Score Rank
BMW 550i 7.0 1
Infiniti M56 7.0 1

Instrument Panel (IP) Layout
Vehicle Score Rank
BMW 550i 7.5 1
Infiniti M56 7.5 1

Climate Control Layout
Vehicle Score Rank
BMW 550i 8.0 1
Infiniti M56 7.0 2

Audio System Layout
Vehicle Score Rank
BMW 550i 7.0 2
Infiniti M56 7.8 1

Secondary Control Layout
Vehicle Score Rank
BMW 550i 7.5 1
Infiniti M56 7.0 2

Interior Storage
Vehicle Score Rank
BMW 550i 7.3 2
Infiniti M56 7.8 1

Cupholders
Vehicle Score Rank
BMW 550i 7.8 1
Infiniti M56 6.5 2

Standard Cargo / Trunk Space
Vehicle Score Rank
BMW 550i 7.0 2
Infiniti M56 8.0 1

Maximum Cargo Space
Vehicle Score Rank
BMW 550i 9.0 1
Infiniti M56 7.0 2

Dimensions
Engine & Transmission Specifications
Warranty Information
Performance Information


Dimensions
Exterior Dimensions & Capacities
  BMW 550i Infiniti M56
Length, in. 193.1 194.7
Width, in. 73.2 72.6
Height, in. 57.6 59.1
Wheelbase, in. 116.9 114.2
As Tested Curb Weight, lb. 4,380 4,093
Turning Circle, ft.    


Interior Dimensions
  BMW 550i Infiniti M56
Front headroom, in. 40.5 39.1
Rear headroom, in. 38.3 37.7
Front shoulder room, in. 58.3 58.4
Rear shoulder room, in. 56.2 56.7
Front legroom, in. 41.4 44.0
Rear legroom, in. 36.1 36.2
Cargo volume, cu-ft. 18.4 14.9
Max cargo volume, cu-ft.    


Engine & Transmission Specifications
Engine & Transmission
  BMW 550i Infiniti M56
Displacement
(cc / cu-in):
4400 (269) 5600 (342)
Engine Type V8 V8
Horsepower (SAE) @ rpm 400 @ 5,500 420 @ 6,000
Max. Torque, lb-ft @ rpm 450 @ 1,750 417 @ 4,400
Transmission 8-speed automatic 7-speed automatic
EPA Fuel Economy City, mpg 15.0 16.0
EPA Fuel Economy Hwy, mpg 22.0 25.0
Observed Fuel Economy combined, mpg 18.6 18.0


Warranty
Warranty Information
  BMW 550i Infiniti M56
Basic Warranty 4 years/50,000 miles 4 years/60,000 miles
Powertrain 4 years/50,000 miles 6 years/70,000 miles
Roadside Assistance 4 years/Unlimited miles 4 years/60,000 miles
Corrosion Protection 12 years/Unlimited miles 7 years/Unlimited miles


Performance
Performance Information
  BMW 550i Infiniti M56
0-60 mph acceleration, sec. 5.2 5.0
Quarter-mile acceleration, sec. 13.2 13.3
Quarter-mile speed, mph 108.3 106.7
60-0-mph braking, feet 114 113
Lateral Acceleration, g 0.84 0.89
600-ft slalom, mph 65.5 66.7

Final Rankings
Item Weight BMW 550i Infiniti M56
Personal Rating 2.5% 75.0 75.0
Recommended Rating 2.5% 100.0 50.0
Evaluation Score 20% 77.1 73.5
Feature Content 20% 61.9 52.4
Performance 25% 94.3 98.3
Fuel Consumption 10% 100.0 97.3
Price 20% 95.1 100.0
Total Score 100.0% 84.8 82.6
Final Ranking 1 2


Personal Rating (2.5%): Purely subjective. After the test, each participating editor was asked to rank the sedans in order of preference based on which he or she would buy if money were no object.

Recommended Rating (2.5%): After the test, each participating editor was asked to rank the sedans in order of preference based on which he or she thinks would be best for the typical midsize luxury sedan buyer.

28-Point Evaluation Score (20%): Each participating editor scored each vehicle based on a comprehensive 28-point evaluation. The evaluation covered everything from control feel to cupholders. Scoring is calculated on a point system, and the scores listed are averages based on all test participants' evaluations.

Feature Content (20%): Features are a big deal in midsize luxury sedans, and you can expect to find leading-edge technology in both of these cars. We've picked seven key features that we thought were essential in a luxury sport sedan. For each sedan, the score is based on the number of actual features it has versus the total possible (seven). Standard and optional equipment were taken into consideration.

Performance (25%): Each vehicle is run through Inside Line's regimen of standardized instrumented tests: acceleration (0-60 and quarter-mile), braking (60-0), 600-foot slalom and 200-foot-diameter skid pad. Points are awarded as a percentage of the best overall performance in each test. Note that we've weighted performance a hefty 25 percent, given our feeling that if you're looking at V8-equipped premium sedans, performance is clearly a big factor for you.

Fuel Consumption (10%): The scores listed are the result of a simple percentage calculation based on the car with the highest EPA combined fuel economy rating (55 percent city plus 45 percent highway).

Price (20%): The numbers listed are the result of a simple percentage calculation based on the less expensive of the two sedans in this comparison test. Using the "as tested" prices of the actual evaluation vehicles, the lower-priced Infiniti M56 received a score of 100, with the BMW 550i receiving a proportionally lesser score.

Vehicle
Model year2011
MakeBMW
Model5 Series 550i
Year Make Model2011 BMW 5 Series 550i 4dr Sedan (4.4L 8cyl Turbo 8A)
Vehicle TypeRWD 4dr 5-passenger Sedan
Base MSRP$60,575
Options on test vehicleTitanium Silver Metallic (no charge); Premium Package 2 ($2,800 -- includes rearview camera; power rear window shade and manual rear side window shades; heated front seats with three levels of heat intensity; Sirius Satellite Radio, including a 1-year subscription to Sirius Satellite service; 16-neodymium-speaker audio system with 600-watt, 9-channel amplifier and vehicle speed-dependent equalization; iPod and USB adapter); Dynamic Handling Package ($2,700 -- includes Dynamic Damper Control variable rate electromagnetic shock absorbers; Active Roll Stabilization [ARS] hydroelectrically actuated stabilizer bars); Sport Package ($2,200 -- includes sports leather steering wheel; 19-by-8.5-inch front and 19-by-9-inch rear W-spoke [style 332] alloy wheels with 245/40R19 front and 275/35R19 rear run-flat performance tires; increased top speed limiter; multicontour 20-way [14-way power adjustments, two-way power headrests and four-way power lumbar support] front power seats; active head restraints for the front seats; memory settings for the front passenger seat; Shadowline exterior window trim); Convenience Package ($1,700 -- includes power tailgate; Comfort Access keyless entry; soft-close automatic doors); Split-Fold-Down Rear Seat ($475); Steptronic Automatic Transmission ($0 -- includes eight-speed Steptronic automatic transmission).
As-tested MSRP$70,450
Assembly locationDingolfing, Germany
North American parts content (%)5
Drivetrain
ConfigurationLongitudinal, front-engine, rear-wheel drive
Engine typeTwin-turbocharged direct-injected V8, gasoline
Displacement (cc/cu-in)4,395cc (268 cu-in)
Block/head materialAluminum, aluminum
ValvetrainDOHC, four valves per cylinder, variable intake + exhaust-valve timing
Compression ratio (x:1)10.0
Redline, indicated (rpm)6,750
Horsepower (hp @ rpm)400 @ 5,500
Torque (lb-ft @ rpm)450 @ 1,750
Fuel typePremium unleaded (required)
Transmission typeEight-speed automatic with console shifter with sport/competition modes
Transmission ratios (x:1)1st = 4.714, 2nd = 3.143, 3rd = 2.106, 4th = 1.667, 5th = 1.285, 6th = 1.000, 7th = 0.839, 8th = 0.667
Final-drive ratio (x:1)2,.813
Differential(s)Electronic limited-slip rear differential
Chassis
Suspension, frontIndependent multilink, coil springs, self-adjusting variable dampers, lower control arms, self-adjusting, active, stabilizer bar
Suspension, rearIndependent multilink, coil springs, self-adjusting variable dampers, self-adjusting, active, stabilizer bar
Steering typeElectric speed-proportional power steering
Steering ratio (x:1)17.1
Tire make and modelGoodyear Excellence
Tire typeAll-season front and rear
Tire size, frontP245/40R19 94Y
Tire size, rearP275/35R19 96Y
Wheel size, front19-by-8.5 inches
Wheel size, rear19-by-9 inches
Wheel materialAlloy
Brakes, front14.7-inch ventilated steel discs with single-piston sliding calipers
Brakes, rear14.6-inch ventilated steel discs with single-piston sliding calipers
Track Test Results
Acceleration, 0-30 mph (sec.)2.1
0-45 mph (sec.)3.5
0-60 mph (sec.)5.2
0-75 mph (sec.)7.1
1/4-mile (sec. @ mph)13.2 @ 108.3
0-60 with 1 foot of rollout (sec.)4.9
0-30 mph, trac ON (sec.)2.3
0-45 mph, trac ON (sec.)3.7
0-60 mph, trac ON (sec.)5.5
0-75 mph, trac ON (sec.)7.5
1/4-mile, trac ON (sec. @ mph)13.4 @ 106.5
0-60, trac ON with 1 foot of rollout (sec.)5.0
Braking, 30-0 mph (ft.)28
60-0 mph (ft.)114
Slalom, 6 x 100 ft. (mph)65.5
Slalom, 6 x 100 ft. (mph) ESC ON62.6
Skid pad, 200-ft. diameter (lateral g)0.84
Skid pad, 200-ft. diameter (lateral g) ESC ON0.84
Sound level @ idle (dB)35.8
@ Full throttle (dB)74.3
@ 70 mph cruise (dB)64.5
Engine speed @ 70 mph (rpm)2,200
Test Driver Ratings & Comments
Acceleration commentsConsidering that the BMW 550i weighs almost 4,400 pounds, it gets off the line well. But it really came alive when power braking with stability and traction control turned off, allowing for a near-perfect amount of wheelspin. The third run overall (first with power braking) was quickest, but the final (sixth) run was barely any slower, showing good aversion to heat soak.
Braking commentsAlthough braking distances varied by several feet with each run, randomly longer and shorter over the first five stops, the BMW's pedal travel barely changed and its feel remained very solid, while control under panic braking was always stable.
Handling commentsSkid pad: The BMW's all-season run-flat tires did the best they could around the skid pad, hampered by the car's soft suspension and hefty curb weight. Attitude is steady-state understeer. It was possible to circle at nearly full throttle with the stability system turned on, the computer cutting power to keep the car from straying off line. Slalom: Not easy due to slow-reacting, lackluster-feeling electric steering, but the chassis offers decent feedback. The stability system wasn't overly intrusive when it came on, but you can go faster without it.
Testing Conditions
Test date10/26/2010
Test locationCalifornia Speedway
Elevation (ft.)1,121
Temperature (F)58.4
Relative humidity (%)72.7
Barometric pressure (in. Hg)28.8
Wind (mph, direction)0.6, head/crosswind
Odometer (mi.)3,875
Fuel used for test91-octane gasoline
As-tested tire pressures, f/r (psi)35/38
Fuel Consumption
EPA fuel economy (mpg)17 city/25 highway/20 combined
Edmunds observed (mpg)18.6
Fuel tank capacity (U.S. gal.)18.5
Driving range (mi.)463
Audio and Advanced Technology
Stereo description16 neodymium speaker audio system with 600-watt, 9-channel amplifier and vehicle speed-dependent equalization; iPod and USB adapter.
iPod/digital media compatibilityOptional iPod via propietary cable USB stick
Satellite radioOptional Sirius
Hard-drive music storage capacity (Gb)Not available
Rear seat video and entertainmentOptional
Bluetooth phone connectivityStandard
Navigation systemStandard hard drive
Telematics (OnStar, etc.)Standard 48 months trial subscription
Smart entry/StartOptional -- ignition, doors, trunk
Parking aidsOptional back-up camera and automated self-parking system
Blind-spot detectionOptional
Adaptive cruise controlOptional
Lane-departure monitoringOptional departure warning
Collision warning/avoidanceOptional
Night VisionOptional
Driver coaching displayStandard current mpg display
Dimensions & Capacities
Curb weight, mfr. claim (lbs.)4,343
Curb weight, as tested (lbs.)4,380
Weight distribution, as tested, f/r (%)52/48
Length (in.)193.1
Width (in.)73.2
Height (in.)57.6
Wheelbase (in.)116.9
Track, front (in.)63.0
Track, rear (in.)64.1
Turning circle (ft.)39.2
Legroom, front (in.)41.4
Legroom, rear (in.)36.1
Headroom, front (in.)40.5
Headroom, rear (in.)38.3
Shoulder room, front (in.)58.3
Shoulder room, rear (in.)56.2
Seating capacity5
Step-in height, measured (in.)15.8
Trunk volume (cu-ft)18.4
Cargo loading height, measured (in.)27.0
GVWR (lbs.)5,423
Payload, mfr. max claim (lbs.)1,036
Tow capacity, mfr. claim (lbs.)Not Published
Ground clearance (in.)5.6
Warranty
Bumper-to-bumper4 years/50,000 miles
Powertrain4 years/50,000 miles
Corrosion12 years/Unlimited miles
Roadside assistance4 years/Unlimited miles
Free scheduled maintenance4 years/50,000 miles
Vehicle
Model year2011
MakeInfiniti
ModelM56
Year Make Model2011 Infiniti M56 4dr Sedan (5.6L 8cyl 7A)
Vehicle TypeRWD 4dr 5-passenger Sedan
Base MSRP$58,765
Options on test vehicleMoonlight White; Sport Package ($3,650 -- includes 20-by-9-inch split five-spoke aluminum-alloy wheels with 245/40R20W-rated summer performance tires; sport-tuned suspension with upgraded springs and double-piston shock absorbers; sport brakes with aluminum four-piston opposed front calipers/two-piston opposed rear calipers; four-wheel active steer; solid magnesium paddle shifters; sport seat with enhanced bolstering; aluminum pedal accents; premium stitched meter hood; sport steering wheel and shift knob; unique front fascia; dark front grille and headlamp housing); Sport Touring Package ($2,000 -- includes Bose studio surround-sound system with digital 5.1-channel decoding, 16 speakers, Forest Air system with advanced auto recirculation, Breeze mode, Plasmacluster air purifier and grape polyphenol filter, power rear sunshade); Aerodynamic Package ($1,995); R Spec High-Friction Brake Pads ($370); Illuminated Kick Plates ($350).
As-tested MSRP$67,130
Assembly locationTochigi, Japan
North American parts content (%)0%
Drivetrain
ConfigurationLongitudinal, front-engine, rear-wheel drive
Engine typeNaturally aspirated, direct-injected gasoline V8
Displacement (cc/cu-in)5,552cc (339 cu-in)
Block/head materialAluminum/aluminum
ValvetrainDOHC, four valves per cylinder, variable intake + exhaust-valve timing and lift
Compression ratio (x:1)11.5
Redline, indicated (rpm)6,700
Fuel cutoff/rev limiter (rpm)6,750
Horsepower (hp @ rpm)420 @ 6,000
Torque (lb-ft @ rpm)417 @ 4,400
Fuel typePremium unleaded (required)
Transmission typeSeven-speed automatic with console shifter and column-mounted paddles with sport/competition modes
Transmission ratios (x:1)1st = 4.783, 2nd = 3.103, 3rd = 1.984, 4th = 1.371, 5th = 1.000, 6th = 0.871, 7th = 0.776
Final-drive ratio (x:1)2.611
Chassis
Suspension, frontIndependent double-wishbones, coil springs, monotube dampers, stabilizer bar
Suspension, rearIndependent multilink, coil springs, monotube dampers, stabilizer bar
Steering typeHydraulic-assist, speed-proportional rack-and-pinion power steering with active rear-steer
Steering ratio (x:1)16.9
Tire make and modelBridgestone Potenza RE050A
Tire typeAsymmetrical summer high-performance (33 psi cold front; 33 psi cold rear)
Tire sizeP245/40R20 95W
Wheel size20-by-9 inches front and rear
Wheel materialCast aluminum
Brakes, front14-inch one-piece ventilated steel discs with four-piston fixed calipers
Brakes, rear13.8-inch one-piece ventilated steel discs with two-piston fixed calipers
Track Test Results
Acceleration, 0-30 mph (sec.)2.2
0-45 mph (sec.)3.4
0-60 mph (sec.)5.0
0-75 mph (sec.)7.2
1/4-mile (sec. @ mph)13.3 @ 106.7
0-60 with 1 foot of rollout (sec.)4.7
0-30 mph, trac ON (sec.)2.5
0-45 mph, trac ON (sec.)3.7
0-60 mph, trac ON (sec.)5.3
0-75 mph, trac ON (sec.)7.6
1/4-mile, trac ON (sec. @ mph)13.5 @ 105.8
0-60, trac ON with 1 foot of rollout (sec.)4.9
Braking, 30-0 mph (ft.)29
60-0 mph (ft.)113
Slalom, 6 x 100 ft. (mph)66.7
Slalom, 6 x 100 ft. (mph) ESC ON64.9
Skid pad, 200-ft. diameter (lateral g)0.89
Skid pad, 200-ft. diameter (lateral g) ESC ON0.83
Sound level @ idle (dB)34.1
@ Full throttle (dB)80.3
@ 70 mph cruise (dB)67.7
Engine speed @ 70 mph (rpm)1,750
Test Driver Ratings & Comments
Acceleration commentsTurning the stability control system off made no difference in the way the M56 launched. But power braking did affect numbers, despite the fact that the system would only allow about 1,600 rpm. Regardless, we never got any wheelspin at the drag strip. Although the M56 would start a bit sluggishly off the line, its naturally aspirated V8 revved very hard once under way.
Braking commentsVery good brake performance in terms of stopping distances, lack of fade and pedal feel. The pedal actually got less spongy the more stops we did; the optional R Spec high-friction brake pads probably help here.
Handling commentsSkid pad: The Infiniti is very sensitive to throttle input. Its line around the skid pad is therefore very correctable, but if you get too aggressive with drop-throttle to tighten the line, it will oversteer and ruin the run. Slalom: The Infiniti's steering is quick, a bit more so than you'd expect in a car of this size. But it hustles around the slalom cones pretty quickly with ESC off. ESC on allows a fair amount of oversteer before it starts adding brakes to the wheels -- but it's abrupt and speed-sapping when it does.
Testing Conditions
Test date10/26/2010
Test locationCalifornia Speedway
Elevation (ft.)1,121
Temperature (F)57.9
Relative humidity (%)75.4
Barometric pressure (in. Hg)28.8
Wind (mph, direction)3.5, head/cross wind
Odometer (mi.)3,550
Fuel used for test91-octane gasoline
As-tested tire pressures, f/r (psi)33/33
Fuel Consumption
EPA fuel economy (mpg)16 city/25 highway/19 combined
Edmunds observed (mpg)18.0
Fuel tank capacity (U.S. gal.)20.0
Driving range (mi.)500
Audio and Advanced Technology
Stereo descriptionBose Studio Surround with digital 5.1-channel decoding, 16 speakers
iPod/digital media compatibilityStandard iPod via USB jack
Satellite radioStandard XM
Hard-drive music storage capacity (Gb)Standard 9.3GB music storage capacity
Rear seat video and entertainmentNot available
Bluetooth phone connectivityStandard (includes music streaming)
Navigation systemStandard hard drive with XM traffic, 8.0-inch VGA touchscreen display
Telematics (OnStar, etc.)None
Smart entry/StartStandard ignition/doors
Parking aidsStandard back-up camera
Blind-spot detectionOptional
Adaptive cruise controlOptional
Lane-departure monitoringOptional lane departure warning
Collision warning/avoidanceOptional
Night VisionNot available
Driver coaching displayStandard throttle pedal feedback in "Eco" mode, current/average mpg display
Dimensions & Capacities
Curb weight, mfr. claim (lbs.)4,028
Curb weight, as tested (lbs.)4,093
Weight distribution, as tested, f/r (%)55/45
Length (in.)194.7
Width (in.)72.6
Height (in.)59.1
Wheelbase (in.)114.2
Track, front (in.)62.0
Track, rear (in.)61.8
Turning circle (ft.)36.7
Legroom, front (in.)44.0
Legroom, rear (in.)36.2
Headroom, front (in.)39.1
Headroom, rear (in.)37.7
Shoulder room, front (in.)58.4
Shoulder room, rear (in.)56.7
Seating capacity5
Step-in height, measured (in.)16.0
Trunk volume (cu-ft)14.9
Cargo loading height, measured (in.)28.8
GVWR (lbs.)5,143
Ground clearance (in.)5.9
Warranty
Bumper-to-bumper4 years/60,000 miles
Powertrain6 years/70,000 miles
Corrosion7 years/Unlimited miles
Roadside assistance4 years/60,000 miles
Free scheduled maintenanceNot available

Comments

  • abnrgr1 abnrgr1 Posts:

    Figures. The Infiniti has more HP, is 0.2 seconds faster 0-60, is 1.2 mph faster through the slalom, blows the BMW away on the skidpad .89 to a lousy .84, has a better interior, is a better value initially and if history is any judge I'd be a lot more worried once the Bimmer is out of warranty than the Infiniti.....YET, the winner is somehow the BMW. The reason? Because it has a better ride?! Funny I thought these were Sports Sedans. I tend to think if the BMW had all those better numbers and interior etc and the Infiniti was better in the ride category, the winner would have been the BMW, because it won most of the head to head tests and it cornered appreciably better than the Infiniti which felt "uninvolved." Heaven forbid a Japanese car is chosen over a German car, even when it wins a head to head test.

Leave a Comment

Research Models

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT

Edmunds Insurance Estimator

TCO® insurance data for this vehicle coming soon...

For an accurate quote, contact our trusted partner below.

* Explanation
ADVERTISEMENT