Infiniti FX

From Infiniti press: Already a strong contender in the competitive performance luxury SUV segment, the all-new, second-generation Infiniti FX performance luxury crossover SUV takes a major step forward with a newly designed 5.0-liter V8, enhanced 3.5-liter V6, new standard 7-speed automatic transmission, enhanced exterior styling, advanced interior design and innovative technology and safety equipment.

The FX is offered in two models – FX50 and FX35 – each designating their respective engine sizes.  The FX50’s advanced 5.0-liter V8 is a new powerplant, while the FX35’s 3.5-liter V6 was recently introduced in the popular Infiniti G35 Sedan.  Both engines are mounted low in the chassis to help lower the FX’s center of gravity.

The goals for the development of the FX’s all-new VK50VE V8 started with outstanding power output – 390 horsepower at 6,500 rpm and 369 lb-ft of torque at 4,400 rpm (versus the previous generation FX45’s 320 horsepower and 335 lb-ft of torque) – a high rev limit, a powerful engine sound from a specially tuned exhaust and improved fuel economy versus the previous 4.5-liter V8. 

The engine design also includes twin symmetrical air intakes, titanium valves, modular cylinder heads, microfinished crankshaft, lightweight pistons, super-silent single stage cam drive chains and a hydraulically driven cooling fan to help optimize performance.  Even small details were evaluated in designing the new engine, including how the oil mist circulates within the engine for reduced friction.

Both all-wheel drive and rear-wheel drive FX35 models come equipped with a standard 3.5-liter DOHC 24-valve V6 engine with aluminum block and heads and electronically controlled throttle system. 

The V6 has been tuned specifically for use in the FX35, with a rating of 303-horsepower at 6,800 rpm (versus the previous generation FX35’s 275 horsepower) and 262 lb-ft of torque at 4800 rpm, and is expected to offer similar acceleration to the previous V8-equipped FX45 – along with improved fuel efficiency versus the outgoing model.

The VQ-series V6, which has been named one of the “Ten Best Engines” by Ward’s Auto World magazine for 14 consecutive years, is now in its fourth generation.  The block features ladder frame construction for greater rigidity and standard variable exhaust cam timing (CVTCS), a high redline 7,500 and high compression ratio (10.6:1), asymmetric piston skirts, twin knock sensors, improved coolant flow and double fine-tipped Iridium spark plugs.

Gallery: Infiniti FX