From Infiniti press: For 2009, the Infiniti M mid-size premium performance sedan is again offered with a choice of 4.5-liter V8 and 3.5-liter V6 engines and with rear-wheel drive or ATTESA E-TS™ all-wheel drive. The major enhancements for the new model year include a new, more powerful V6 engine for the M35 and M35x and the addition of a new 7-speed automatic transmission for all M35 RWD model. The 2009 Infiniti M is available in four models – M35 RWD, M35x AWD, M45 RWD and M45x AWD.
The M35’s new VQ35HR 3.5-liter V6 engine, which is rated at 303 horsepower and 262 lb-ft of torque, replaces the previous 275-horsepower 3.5-liter V6. Versions of this new engine are also utilized in the new second-generation 2009 Infiniti FX35. The Infiniti M45 continues to offer a standard 325-horsepower 4.5-liter aluminum-alloy DOHC V8 and an advanced 5-speed automatic transmission.
For 2009, the Infiniti M is again offered in V8-equipped M45 or V6-equipped M35 models. The M45 features a standard DOHC 4.5-liter V8 rated at 325 horsepower and 336 lb-ft of torque. The engine design includes titanium valves, modular cylinder heads, microfinished crankshaft, lightweight pistons and super-silent single stage cam drive chain to help optimize performance. In addition, the VK45DE is outfitted with a variable length air induction system and Continuously Variable Valve Timing Control System (CVTCS) to enhance the engine’s power delivery and operation efficiency.
The M45 comes standard with an advanced 5-speed automatic transmission with manual shift mode, Downshift Rev Matching and a new Drive Sport (DS) mode, which provides better acceleration feel and a more sporting driving experience.
For 2009, the Infiniti M35 receives a new, advanced DOHC 3.5-liter V6 rated at 303 horsepower and 262 lb-ft of torque – an increase of 28 horsepower over the previous 3.5-liter V6. The engine includes aluminum-alloy block and heads and electronically controlled “drive-by-wire” throttle system. Fuel economy improves to 17 mpg City/25 mpg Highway (from 16/23 mpg City/Highway) despite the increase in horsepower.
Two transmissions are offered with the V6 engine – a 5-speed automatic transmission with the all-wheel drive M35x and a new 7-speed automatic with the rear-wheel drive M35. Both transmissions feature a manual shift mode, Downshift Rev Matching and Drive Sport (DS) mode.