Vehicle Overview Infiniti’s midsize sport sedan comes in M35 and M45 versions, denoting the 3.5-liter V-6 and 4.5-liter V-8, respectively, that power them. The car comes in rear- and all-wheel-drive variants, the latter called M35x and M45x. This report covers the M45 and M45x; the M35 and M35x are listed separately in Cars.com’s Research section. Competitors to the M include the Lexus GS, BMW 5 Series and Mercedes-Benz E-Class.
New for 2009 Changes for this year’s M45 and M45x are relatively few. Infiniti’s Scratch Shield paint, which uses a clearcoat resin to gradually smooth over minor scratches, is new.
Exterior Infiniti promotes the M’s “low, aggressive hoodline [that] flows into the anchored shoulders.” The body has short overhangs and a long, 114.2-inch wheelbase. Lightweight body components include aluminum-alloy deck-lid panels, inner and outer door panels, and hood. A rear spoiler is available. The optional Sport Package adds unique exterior trimmings, though it’s only available on the rear-wheel-drive M45.
Standard 18-inch alloy wheels
Standard xenon headlights
Standard keyless access with push-button startup
Sport Package adds unique bumpers, headlights and side sills, plus 19-inch wheels
Rear Active Steer angles rear wheels during turns to improve handling (Sport Package)
Interior The M sedan seats five in a well-appointed interior with textured wood or aluminum trim. Interior volume, at 105.2 cubic feet (103.1 cubic feet with the Premium Package), ranks between the GS and Infiniti’s less-spacious European competitors. Cabin features include:
Power-adjustable front seats
Heated and cooled front seats
Moonroof
Dual-zone automatic climate control
Six-speaker, six-CD stereo
Available eight-speaker, two-channel or 14-speaker, 5.1-channel surround-sound stereos, both by Bose
Available backseat DVD player
Available navigation system and backup camera
Available heated and power-reclining rear seats
Under the Hood The M45 and M45x continue with a 4.5-liter V-8. The five-speed automatic adds a Drive-Sport mode, with higher shift points and more aggressive kickdown than regular Drive. Like last year’s auto, it also employs a clutchless-manual mode.
V-8 engine makes 325 horsepower, 336 pounds-feet of torque
Five-speed automatic with Drive-Sport and clutchless-manual modes
Rear- or all-wheel drive
Safety Infiniti’s optional Lane Departure Prevention system applies individual antilock brakes to steer the car as necessary to keep it in its lane. The system uses a camera to recognize lane markings, and it calculates the vehicle’s speed and distance from them. It can be switched off. There’s also a Preview Braking option that scans the road ahead for potential obstructions, including rapidly slowing cars. In such situations, it pre-loads the brakes for sharper response and alerts the driver with an audio chime.
Six airbags, including dual front airbags, side-impact airbags for the front seats and side curtain airbags for both rows
Electronic stability system
Traction control
Active head restraints
Adaptive headlights that swivel several degrees to illuminate oncoming turns
