There"s an old saying, "If it ain't broke, don't fix it." The engineering team behind the new 2017 Nissan Pathfinder has a slightly different perspective – one that aligns closer to, "If it ain't broke, give it more power."
The other guiding principle can be summed up in one word: Balance. Thus it came to be that when giving the new Pathfinder a major injection of adventure juice, they didn't stop at the engine – upping the total driving experience from steering response to flatter cornering to enhanced towing confidence and capability.
Turning to the engine first, the goal was to add more power and torque without compromising fuel efficiency – which meant drawing on a catalog of current, borrowed and new parts and components. Around 43 percent of the new engine"s components were carried over from the proven 2016 Pathfinder engine – including critical systems like the aluminum-alloy block, exhaust valve timing control and intake manifold collector.
From the "something borrowed" category (from other existing Nissan engine designs) came 32 percent of the final components – parts new-to-Pathfinder like the variable displacement oil pump and electronic control module. And that left around 25 percent for new components and technologies, creating what is officially known as the VQ35DD engine.
"Like every area of a vehicle, engines evolve. The key in doing so successfully is in understanding where you are going with the changes," said Michael Bunce, vice president, Product Planning, Nissan North America, Inc. "With the new Pathfinder, the goal wasn't to add raw power, it was to enhance driving feel and confidence across the entire rpm range – whether merging on a freeway on-ramp or pulling a trailer full of watercraft up to a mountain lake."
Starting with the basics – the very basics – the new Pathfinder engine is now cast with a molten iron coating layer (mirror-like finish) on the surface of the cylinder bores. This process, called Mirror Bore Coating, reduces friction between the piston ring and the cylinder wall. Just as important, it eliminates the need for the traditional cast iron cylinder liners (six total), thus making the aluminum cylinder lighter by around three pounds. “While three pounds might not seem like much outside of racing applications, it allows additional componentry to be added without increasing overall weight,” explained Bunce.
Along with the improved cylinder lining method, the engine features new pistons, a new air intake system – which enhances torque and horsepower – and the new fully electronic timing on the intake side. The compression ratio has also been raised to 11.0:1 (from the previous 10.3:1).
The engine"s new Direct Injection Gasoline™ (DIG) system, which is also utilized on the all-new flagship Nissan Armada full-size SUV, provides better wide-open throttle performance and improved fuel economy and emissions performance (versus a non-direct-injection system). The system injects fuel directly into the combustion chamber rather than into the intake port. The designated shape of the piston head controls the injected fuel flow to the spark plug. This introduces concentrated fuel around the spark plug, reducing the time needed to burn the fuel. This also helps eliminate residual fuel buildup, resulting in cleaner exhaust.
Horsepower for the new Pathfinder V6 is now 284 hp at 6,400 rpm (from the previous 260 hp) and torque is now rated at 259 lb-ft at 4,800 rpm (up from 240 lb-ft). And, while adding more horsepower and torque, Pathfinder fuel economy remains 20 mpg city, 27 mpg highway and 22 mpg combined for 2WD models (estimated).
All 2017 Pathfinder models are equipped with Nissan"s third-generation Xtronic transmission (similar to that utilized in the sporty Nissan Maxima). The Xtronic transmission includes the latest D-Step Logic Control, which simulates shifts, giving a more natural acceleration feeling.
"Building on Pathfinder's already highly capable adventure credentials, the revised 3.5-liter V6 helps provide real world driving benefits – more responsive acceleration and re-acceleration when entering highways or passing," said Bunce. "Matching the added power and torque are enhancements to towing capacity and ride and handling due to revised suspension setting and 11 percent quicker steering versus the 2016 Pathfinder. Even the tires have new compounds and tread designs, helping provide quicker turn-in and balance, along with reduced understeer."
Maximum towing capacity has increased by 1,000 pounds to a best-in-class* 6,000 pounds (when properly equipped) due to the enhanced powertrain and body reinforcements added around the trailer hitch area. The advanced Xtronic transmission design also helps keep engine rpm optimized while towing without the typical "hunting for a gear" feel.
Among the revised or retuned suspension components are 11 percent stiffer front shock absorbers and seven percent stiffer rear shocks. Rebound springs have been added to the front struts to help assist with roll balance and body control. The spring rates of the rear rebound springs have also been increased by 25 percent (both versus 2016 model).
"From behind the wheel, the Pathfinder feels like a totally new vehicle, which in many ways it is," concluded Bunce.