The Infiniti FX (FX35) and QX70 (FX50S) are a series of luxury crossover SUVs produced by Nissan's premium brand, Infiniti. The S51 trim level was introduced in 2009 as an upgrade to the previous model.
Design and Features
The Infiniti FX/QX70 S51 features a sporty exterior design with a sloping roofline, rounded wheel wells, and angular headlights.
It comes with a choice of two engines: a 3.5-liter V6 (FX) producing 303 horsepower or a 3.7-liter V6 (QX70S) delivering 325 horsepower in the S51 trim.
A 7-speed automatic transmission is standard on both models, while a manual mode allows drivers to take control of gear shifts.
The QX70S features a more aggressive front bumper, larger air intakes, and a distinctive rear diffuser.
Standard safety features include dual-stage front airbags, side curtain airbags, and anti-lock braking (ABS) with electronic brakeforce distribution.
Interior and Comfort
The FX/QX70 S51 interior is designed to provide comfort and luxury, featuring premium leather upholstery, heated seats, and a 10-speaker Bose sound system.
A navigation system, Bluetooth connectivity, and an Infiniti-unique "Intelligent Key" system are standard features.
Rear legroom is relatively spacious, but not as generous as some competitors.
The QX70S features exclusive interior trim materials, such as carbon fiber and aluminum.
Performance
The 3.5-liter V6 engine in the FX produces 303 horsepower and can accelerate from 0-60 mph in around 7 seconds.
The more powerful 3.7-liter V6 (QX70S) generates 325 horsepower and achieves a faster acceleration time of approximately 6 seconds to 60 mph.
Warranty and Maintenance
Infiniti offers a comprehensive warranty package for the FX/QX70 S51, including a 4-year/60,000-mile basic vehicle warranty and a 5-year unlimited-mileage powertrain warranty.
Regular maintenance is relatively affordable, with recommended services every 7,500 miles.
Reliability and Safety
The Infiniti QX70 has received generally positive reviews for its reliability and safety features.
In government crash tests (2012-2013), the FX/QX70 S51 earned a perfect 5-star rating in frontal and side impact crashes.
Additionally, it was named a "Top Pick" by the Insurance Institute for Highway Safety (IIHS) for its impressive performance in moderate overlap front crashes.
Comparison to Other Models
The Infiniti QX70 competes directly with other luxury SUVs like the BMW X5 35i, Audi Q7 3.0T, and Mercedes-Benz ML350.
While the FX/QX70 S51 boasts strong performance and a comfortable ride, some critics have noted its limited cargo space and lower towing capacity compared to rivals.
Specifications
Engine: 3.5-liter V6 (FX), 3.7-liter V6 (QX70S)
Transmission: 7-speed automatic
Drive Type: All-wheel drive (AWD) with intelligent torque distribution
Curb Weight: Approximately 4,300-4,400 pounds (depending on engine choice and trim level)
Price History
The base price of the Infiniti FX35 S51 in 2009 was around $44,000.
By 2013, prices had increased to approximately $47,000 for the QX70S.
Recall History
In 2012, Infiniti recalled over 6,500 FX and QX70 models due to a software glitch that could cause unintended acceleration.
A separate recall in 2011 affected around 22,000 units of various Infiniti models, including the FX/QX70 S51, for an issue with the brake system's electronic control module.