Most reviewers agree with TheCarConnection.com in saying that the standard 303-horsepower V-6 will be plenty fast, and the engine is still among the sweetest V-6 units around. The V-8 is even faster, but the V-6 version with rear-wheel drive is clearly the best-handling of the bunch, with all-wheel-drive models possessing a different steering feel and V-8s seeming noticeably heavier. Overall, steering feel is about as good as it gets in a utility vehicle of any kind.
It’s clear that Car and Driver appreciates the performance in the FX50. “This new V-8 packs a mega-punch. We saw 60 mph flash past in 5.0 seconds in our FX50S, with the quarter-mile dispatched in 13.6 seconds at 104 mph. That’s quicker than a Mustang GT.”
Regarding the FX35, Car and Driver says that “performance is hardly shabby,” citing a 0-60 time of just 6.1 seconds. ConsumerGuide, though, feels that the Infiniti FX35 is just "adequately powerful on the highway."
Motor Trend says, “Power comes quickly and effortlessly as the FX50 rockets to speed, and the transmission makes it easy to keep things in check when descending steep grades.” ConsumerGuide also notes that the "busy 7-speed automatic is indecisive and too quick to shift during hill climbs or highway passing maneuvers."
Autoblog reviewers say when taking the FX on back roads, the FX's capabilities make them feel "less than impressed." Additionally, "shifts are somewhat sluggish and the paddle shifters aren't nearly as immediate as they need to be." In contrast, “the engine and transmission are well matched,” according to Motor Trend, while Car and Driver comments that the transmission in the FX50 can shift in a very rough, unrefined way during light acceleration.
Fuel economy is slightly improved with the FX’s redesign for ’09, but it’s still embarrassingly low by some city-dwelling standards, at 16 mpg city, 23 highway with the V-6 (down to 14/20 mpg with the V-8). A further downside: Premium fuel is required for both engines.
In terms of handling, Autoblog raves about the fact that "the four-wheel independent suspension has been recalibrated (double wishbones up front and a multi-link rear setup) and aluminum has been used throughout the new FX, from the suspension to the doors, to shave 200 pounds off the curb weight."
“The best part about the FX35, however, is that it drives better than the FX50,” asserts Car and Driver, pointing to lighter steering, a suppler ride, and a more carlike feel overall.