The 2009 Inifiniti M series boasts adequate performance and a selection of V-6 or V-8 engines, two- or all-wheel drive, and five- or seven-speed automatic transmissions.
Kelley Blue Book provides the specifics on each Infiniti M's performance: "the V6 propels an M35 from 0 to 60 in just over 6 seconds—or slightly more for the heavier AWD M35x...Rated at 325 horsepower and 336 [lb-ft] of torque, the larger V8 in the M45 drops that interval into the mid-to-high five-second range."
Edmunds calls the 2009 Infiniti M's powertrains "impressive" and proclaims, "the M35's V6 should provide more than enough power for most drivers." On the other hand, their editors "praised the Infiniti M45 for its explosive power." In reviews read by TheCarConnection.com, this sentiment is a common theme. Cars.com also appreciates the V-6's power, saying it "churns out fluid power with no peaky burst or low-end sluggishness, and under hard acceleration its high-pitched whine should be music to any gearhead." Of the M45, they report, "It trades the M35's finesse for brute hang-the-tail-out power at pretty much any speed."
Where the 2009 Infiniti Ms fall below the average is fuel economy. According to fueleconomy.gov, an M35 achieves 16 mpg city, 23 highway, while a top-of-the-line M45x gets 14/20 mpg. In ConsumerGuide testing, "rear-drive M35s averaged 16.4 mpg. M35x models averaged 17.4-21.2 mpg with mostly highway use. Test M45s averaged 16 mpg in [mixed] driving." Premium fuel is required for the M45 and recommended for the M35.
Opting for the Infiniti M all-wheel-drive models will "sacrifice a bit of enthusiast appeal," warns Kelley Blue Book, though "Nissan's outstanding AWD system can seamlessly transfer torque from [rear-to-front] and side-to-side as...conditions warrant, making it a feature well worth considering for those who live outside of the Sun Belt." ConsumerGuide notes, "A 50/50 front/rear power split can be locked in via the snow-mode button on the center console." Underpinning the 2009 Infiniti M chassis is an "advanced suspension design [that] responds with just the right mix of compliance and firmness," finds Edmunds. "All Ms have a firm, composed ride," observes ConsumerGuide. "Base M35 and M45 absorb bumps best. M35x has tauter suspension settings, resulting in a slightly less compliant ride."
ConsumerGuide notes, "Steering feel is sporty and precise." They add, "Braking is strong." Infiniti Ms with the Sport Package receive Rear Active Steer, which "varies the geometry of the rear wheels...to deliver even more immediate and positive reactions during spirited cornering," says Kelley Blue Book. Cars.com sums it up well: "All told the steering feel encourages twisty-road driving in a way a Volvo S80 or Mercedes E-Class cannot. Body roll remains well in check, and at its limits the M displays good grip and even better balance."