2017 Nissan Pathfinder Sv 4wd

The 2017 Nissan Pathfinder SV 4WD represents a compelling blend of family practicality and moderate off-road capability. While not a dedicated off-roader, its all-wheel-drive system and robust construction allow it to tackle a wider range of conditions than a typical minivan or sedan. Let's delve into the key engineering aspects that define this particular model.

Powertrain: VQ35DE Under the Hood

The heart of the 2017 Pathfinder SV 4WD is the VQ35DE engine. This is a 3.5-liter, naturally aspirated V6 known for its reliability and smooth power delivery. It's a 60-degree V6, which inherently offers good balance and reduces the need for complex balancing shafts, although Nissan does employ one for further vibration damping. Key features of the VQ35DE include:

Aluminum Block and Heads: This reduces overall engine weight, contributing to improved fuel economy and handling.
Double Overhead Camshafts (DOHC): DOHC configurations allow for greater control over valve timing and lift, leading to improved engine efficiency and power output.
Four Valves Per Cylinder: This design maximizes airflow into and out of the combustion chamber, further enhancing performance.
Variable Valve Timing (VVT): Nissan utilizes a VVT system to optimize valve timing based on engine speed and load. This system improves fuel efficiency at low speeds and boosts power at higher RPMs. The system works by hydraulically adjusting the camshaft position relative to the crankshaft.
Sequential Multiport Fuel Injection: Fuel is injected directly into each intake port, ensuring precise fuel metering and efficient combustion.

The VQ35DE in the 2017 Pathfinder produces around 284 horsepower and 259 lb-ft of torque. This is sufficient for everyday driving and towing, although it's important to remember that the Pathfinder is a relatively heavy vehicle. The engine is known for its longevity, provided it receives regular maintenance, including oil changes and cooling system flushes.

Transmission: Xtronic CVT (Continuously Variable Transmission)

Instead of a traditional automatic transmission with fixed gears, the 2017 Pathfinder uses Nissan's Xtronic CVT. A CVT uses a system of belts and pulleys to provide a virtually infinite number of gear ratios. The advantages of a CVT include:

Improved Fuel Economy: By constantly adjusting the gear ratio to keep the engine in its optimal RPM range, the CVT can improve fuel economy compared to a conventional automatic.
Smooth Acceleration: The CVT eliminates the abrupt shifts associated with traditional automatics, resulting in smoother and more linear acceleration.

However, CVTs also have some drawbacks. Some drivers find the lack of distinct shift points unsettling, and CVTs can sometimes exhibit a "rubber band" effect, where the engine revs up without a corresponding increase in speed. Nissan has attempted to mitigate these issues with simulated gear steps in the Pathfinder's CVT, which mimic the feel of a conventional automatic. The long-term reliability of CVTs has also been a subject of debate, though Nissan has made significant improvements over the years. It is crucial to follow the manufacturer's recommended maintenance schedule for the CVT, including fluid changes, to ensure its longevity.

All-Wheel Drive System: Intelligent 4x4

The "4WD" designation on the Pathfinder SV signifies its Intelligent 4x4 system. This is an electronically controlled all-wheel-drive system that automatically adjusts torque distribution between the front and rear axles based on driving conditions. The system is not a true four-wheel-drive system in the traditional sense, as it does not have a low-range gear for extreme off-roading. However, it provides enhanced traction in slippery conditions such as snow, ice, and mud. Key features of the Intelligent 4x4 system include:

Automatic Mode: In automatic mode, the system operates primarily in front-wheel drive to maximize fuel economy. When the system detects wheel slip, it automatically engages the rear axle to provide additional traction.
4WD Lock Mode: This mode locks the front and rear axles together, providing a 50/50 torque split. This is useful for situations where maximum traction is required, such as driving through deep snow or mud. However, it should only be used at low speeds and for short periods, as it can overheat the system.
Hill Descent Control: This system helps to maintain a constant speed when descending steep hills. The system automatically applies the brakes to each wheel independently, preventing the vehicle from accelerating out of control.
Hill Start Assist: This system prevents the vehicle from rolling backward when starting on a hill. The system holds the brakes for a few seconds, giving the driver time to move their foot from the brake pedal to the accelerator.

The system relies on various sensors, including wheel speed sensors, throttle position sensors, and yaw sensors, to determine the optimal torque distribution. An electronic control unit (ECU) processes this information and sends commands to an electronically controlled coupling, which regulates the amount of torque sent to the rear axle. The Pathfinder's all-wheel-drive system is primarily designed for on-road use and light off-road adventures. It is not intended for serious rock crawling or other extreme off-road activities.

Suspension and Brakes

The 2017 Pathfinder SV 4WD features a four-wheel independent suspension system. This design provides a more comfortable ride and better handling compared to a traditional solid axle suspension. The front suspension consists of MacPherson struts, while the rear suspension uses a multi-link design. The independent suspension allows each wheel to react independently to road imperfections, resulting in a smoother and more controlled ride.

Front Suspension: MacPherson Struts

The MacPherson strut design combines the shock absorber and spring into a single unit, simplifying the suspension design and reducing weight. This design provides good handling and ride comfort.

Rear Suspension: Multi-Link

The multi-link rear suspension uses multiple links to connect the wheel hub to the vehicle's frame. This design allows for greater control over wheel movement, resulting in improved handling and ride comfort. The multi-link design also helps to reduce body roll during cornering.

The Pathfinder is equipped with four-wheel disc brakes with anti-lock braking system (ABS). The ABS prevents the wheels from locking up during hard braking, allowing the driver to maintain steering control. Electronic Brakeforce Distribution (EBD) is also included, which automatically adjusts the braking force between the front and rear wheels to optimize braking performance. Brake Assist is another feature that detects emergency braking situations and applies maximum braking force, even if the driver doesn't press the brake pedal hard enough.

Chassis and Body

The 2017 Pathfinder utilizes a unibody construction, which means that the body and frame are integrated into a single unit. This design provides a stiffer and lighter structure compared to a traditional body-on-frame construction. The unibody construction contributes to improved handling, ride comfort, and fuel economy.

The body panels are made of steel, with some aluminum components used to reduce weight. The Pathfinder's aerodynamic design helps to reduce drag and improve fuel economy. The vehicle also features a number of safety features, including airbags, seatbelt pretensioners, and stability control.

Electronics and Safety Systems

The 2017 Pathfinder SV is equipped with a range of electronic systems designed to enhance safety and convenience. These include:

Vehicle Dynamic Control (VDC): This system helps to prevent skidding by automatically applying the brakes to individual wheels and reducing engine power when necessary.
Traction Control System (TCS): This system prevents wheel spin during acceleration by reducing engine power and applying the brakes to the spinning wheel.
Tire Pressure Monitoring System (TPMS): This system monitors the tire pressure in each tire and alerts the driver if the pressure is too low.
Rearview Camera: This camera provides a view of the area behind the vehicle, making it easier to park and maneuver in tight spaces.
Blind Spot Warning (BSW): This system alerts the driver if there is a vehicle in their blind spot.
Rear Cross Traffic Alert (RCTA): This system alerts the driver if there is a vehicle approaching from the side when backing out of a parking space.

Conclusion

The 2017 Nissan Pathfinder SV 4WD represents a well-engineered package that balances practicality, capability, and comfort. Its VQ35DE engine provides ample power, while the Xtronic CVT offers smooth and efficient performance. The Intelligent 4x4 system provides enhanced traction in a variety of conditions, and the independent suspension delivers a comfortable ride. While not a dedicated off-roader, the Pathfinder is a capable and versatile vehicle that is well-suited for families and those who need a vehicle that can handle a variety of driving conditions. Understanding the interplay of these systems—the engine's valvetrain, the CVT's mechanics, the AWD's torque distribution, and the suspension's geometry—provides a deep appreciation for the engineering that goes into creating a modern SUV like the Pathfinder.