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.
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)
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
- 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
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