2011 Infiniti M56 Track Tested
January 17, 2011
We've had the 2011 Infiniti M56 in our office before and the results have always been the same, "great numbers, but boy does that sport ride get tiring."
Our new Long Term Infiniti M56, however, does not have the sport package. It rolls on 18-inch wheels with all season tires but still has that great 420-horsepower V8 and solid chassis. So it's got some good stuff going and it doesn't have the rough suspension which should add up to a better every day car. But.what's it add up to on the track? This is a sport sedan, right?
Vehicle: 2011 Infiniti M56
Driver: Chris Walton
Drive Type: Rear-wheel drive
Transmission Type: Seven-speed automatic
Engine Type: Naturally aspirated, direct-injected, V8, gasoline
Displacement (cc/cu-in): 5,552 / 339
Redline (rpm): 6,700
Horsepower (hp @ rpm): 420 @ 6,000
Torque (lb-ft @ rpm): 417 @ 4,400
Brake Type (front): 12.6-in one-piece ventilated steel discs with 2-piston sliding calipers
Brake Type (rear): 12.1-in one-piece ventilated steel discs with 1-piston sliding calipers
Steering System: Hydraulic-assist rack-and-pinion power steering
Suspension Type (front): Independent double-wishbones, coil springs, monotube dampers, stabilizer bar
Suspension Type (rear): Independent multilink, coil springs, monotube dampers, stabilizer bar
Tire Size (front): P225/45R 18 91W M+S
Tire Size (rear): P225/45R 18 91W M+S
Tire Brand: Michelin
Tire Model: Primacy HX MXM4
Tire Type: All-season
As Tested Curb Weight (lb): 4,037 (55.8% front)
0-30 (sec): 2.2 (2.4 TC ON)
0-45 (sec): 3.4 (3.6 TC ON)
0-60 (sec): 5.0 (5.2 TC ON)
0-75 (sec): 7.1 (7.3 TC ON)
1/4-Mile (sec @ mph): 13.2 @ 107.3 (13.3 @ 107.4 TC ON)
0-60 with 1-ft Rollout (sec): 4.7 (4.7 TC ON)
30-0 (ft): 30
60-0 (ft): 118
Slalom (mph): 63.5 (62.3 TC ON)
Skid Pad Lateral acceleration (g): 0.86 (0.85 TC on)
Db @ Idle: 42.3
Db @ Full Throttle: 72.4
Db @ 70 mph Cruise: 65.1
Acceleration Comments: There was no advantage to using the transmission's sport mode for acceleration runs -- shift speed and shift RPM were identical to Normal mode (but sport does quicken throttle response and hold gears longer in full Automatic). The M56 wants to creep forward when overlapping pedals, so RPM could not be greatly raised before launch.
Braking Comments: stopping distances were repeatable and fade wasn't an issue; pedal feel was moderately firm. But the pads were smoking heavily after the last stop.
Handling Comments: Skidpad: Does not exhibit the edginess of the sport suspension and summer tire equipped M56. This one pretty much wants to circle the skidpad in a steady understeer push. The ESC was aggressive at cutting the throttle when turned on but the result proved only slightly slower. Slalom: Softer suspension and all-season tires translate to a les precise but more forgiving M56 than the sport package model we previously tested. Still, the chassis remains responsive to the point that you still need to keep on your toes about oversteer- both power on and drop-throttle.