Full Power Captain

It’s a Nissan Ute Jim, but not as we know it!

If you are a Startrek fan you’ll know all about moving into warp drive. While not exactly changing matter into anti-matter, Nissan’s new V6 turbo diesel isn’t far off achieving the impossible.

The end of last year heralded previews of new products due to be launched through 2011, and most of the traditional ute manufacturers and importers trotted out revisions to specifications that added a few kilowatts here and a few Newton-metres there, all adding up to a mild power or torque increase for the latest buyer.

Not so Nissan, which surpassed expectation with its new Navara by announcing an absolute stump puller by comparison.

Available in the top of the line Navara ST-X 550 and shared with the Pathfinder SUV in the Ti 550 model, is a full turbocharged and intercooled, 3.0-litre, V6 diesel with common-rail, direct fuel injection that produces a class-leading 170 kW power at 3,750 rpm and a massive torque output of 550 Nm from 1,750 rpm.

The quest for ultimate power and torque usually comes with a default position on fuel economy, but here, Nissan is claiming the new engine provides the best of both worlds in terms of power and economy. The Alliance developed V6 is claimed to return a fuel consumption figure of 9.5-litres per 100 km on the combined cycle, and has full compliance with the Euro 5 emissions requirements.

And, if you are still reeling in the appreciation of 550 Nm of torque from a 3.0-litre engine in a standard ute weighing in at a typical ute weight of around 1,840 kg, then slow down for a moment and hold your enthusiasm until we get some more figures from Nissan as to the tare or kerb weight figures for the new little truck.Nissan-1

Power and performance comes down to the vehicle power to weight ratio, and, without decrying Nissan the credit for bringing this engine to market, the tare weight of the Pathfinder TI 550 3.0-litre is now over the 2,200 kg weight range, so some of all this extra power and torque is going to be absorbed getting the show on the road and mobile.

Nissan hasn’t actually stated a kerb weight or tare weight for the new ST-X 550 Navara as yet, but it’s not hard to work out that it’s going to be higher than the regular 1,840 kg expected in a crew cab ute. It’s also interesting to find that, for the Pathfinder Ti 550, the stated Gross Vehicle Mass of 2,880 kg is under the quoted trailer towing capability that is listed at 3,500 kg. This means that not only is the accepted maximum trailer weight higher than the kerb weight, which is our standard guide for safety, it’s actually exceeding the gross vehicle mass itself.

So far Nissan has not started quoting the weights for the new Navara, but this top-of-the-range flagship comes pretty much fully loaded. And where better to start than with a seven-speed automatic transmission, the only such gearbox available in Nissan’s light commercial range.

In addition to the new engine and seven-speed automatic gearbox, the new Pathfinder Ti 550 adds privacy glass, auto headlights, sunroof wind deflector, rain-sensing wipers, smoked bonnet protector, side moulding and V6 badges, rear fog lamps and body coloured, heated door mirrors on the outside. While inside, an upgraded DVD player features additional functionality, a nine-speaker Bose audio system and an anti-theft alarm.

For the Nissan Navara ST-X 550, the additional equipment list comprises a tub liner, satin black sportsbar with LED high level brake light, a hard tonneau cover complete with remote central locking, smoked bonnet protector, front fog lights, headlamp washers, privacy glass, roof rails and V6 badges. The maximum payload is 909 kg.

ABS anti-lock braking, Brake Assist (BA) and electric brake distribution (EBD) are all standard, along with Vehicle Dynamic Control (VDC) with Active Brake Limited Slip Differential (ABLS). The safety package includes front to rear curtain airbags, driver and passenger side impact airbags and driver and passenger front impact airbags.

Nissan is understandably extremely vocal in singing the praises of the new engine, illustrating that the Navara, in V6 turbo-diesel guise, manages to produce an impressive 200 Nm torque advantage over its closest rival’s best effort, while the Pathfinder is a muscular 109 Nm stronger than its nearest (and larger) competitor. If nothing else, it fires a broadside over the new five-cylinder engine slated for introduction in the next generation Ford Ranger and Mazda BT-50, and it certainly dims the lights at Volkswagen on the eve of its launch of the 2.0-litre, diesel, four-cylinder engine Amarok.

This new engine, code-named V9X, gives Nissan the muscle to out-manoeuvre Medium SUV category competitors, as well as appeal to buyers of larger Japanese 4×4 wagons. It will also have the torque and image to attract buyers of domestic V8-powered utes, whose growing family, or lifestyle demands, now require additional seats and doors.Nissan-1

The Nissan Navara ST-X 550 is expected to sell for $60,990 and the Pathfinder Ti 550 will retail for $75,990 when they both go on sale in late March.

The V9X engine was revealed at the Geneva Motor Show in March 2010, after a four-year development programme by the engineers of the Renault Nissan Alliance.

The engine features an untypical 65-degree vee angle, which offers an excellent compromise between crankshaft balancing, crankshaft and cylinder block reliability and engine packaging. It also allows enough space for the single turbocharger to be neatly mounted within the vee.

Also unusual is the material from which the engine block is constructed. Unlike the traditional cast iron or aluminium, the development engineers believed that to deliver the desired levels of refinement, an aluminium block would need extra material added to increase its stiffness and reduce noise levels. And while some rivals added complexity, in the form of balancer shafts to boost refinement, these additions negated the aluminium block’s weight advantage.

Conventional cast iron answers the refinement needs, but would have placed too much weight over the front wheels and adversely affect handling characteristics. So the Alliance engineers determined that Compacted Graphite Iron (CGI), a material that offers all the benefits of cast iron, including high levels of stiffness and noise absorption, but without the weight penalty, was the solution.

Although CGI is heavier than a pure alloy block, there is no need to add stiffening ribs or extra sound deadening material, so the weight gain is comparatively modest. It’s also a material well known to makers of heavy truck engines, and it’s likely that use of CGI will continue to spread as engines become more highly stressed through being tapped for more power while increasing the stringent demands of low emissions.

The continuing search for more power, less emissions and greater durability is increasing the operating temperatures of engines, and this in turn raises the stress levels endured by the engine. The use of CGI in engine manufacturing is a well proven solution to this problem.

Experience gained during the development of the acclaimed Alliance 2.0-litre dCi engine, and carrying over some technology, accelerated development of the new V6, but a number of significant changes have been made to the hardware for the V9X.

The combustion chamber design, for example, has been optimised to improve the balance between emission levels and fuel efficiency.

The compression ratio has been lowered to 16:1 to benefit not just economy and emissions but also noise, vibration and harshness (NVH). Internal engine friction is reduced by the use of ultra smooth components such as the micro-finished forged steel used for the crankshaft.

Class leading levels of torque and power outputs are provided through the adoption of a comparatively large single turbocharger, an intercooler and the use of the latest generation of Bosch common-rail fuel injection. This system incorporates piezo injectors and operates at 1800 bar.

Peak torque, of 550 Nm, is achieved from as low as 1700 rpm, and is available all the way to 2500 rpm, while a hefty 500 Nm is available from a mere 1500 rpm. Idle speed is an exceptionally low 650 rpm, with none of the vibrations and noise usually associated with a diesel.

The result is strong low-end performance with comfortably refined delivery and exemplary throttle response. In addition, the engine helps provide strong towing performance, the Pathfinder capable of towing a 3,500 kg braked trailer, with Navara having a 3,000 kg limit.

To achieve Euro 5 compliance, the engineers opted for an overcooled Exhaust Gas Recirculation (EGR) system, which reduces NOx emissions. The system incorporates an integrated exhaust gas by-pass in the EGR cooler that quickly helps to achieve the optimum temperature after start up, so that the full cooling capacity can be used. This features a low temperature water circuit for the EGR cooler to reduce, still further, the temperature of the exhaust gas and lower carbon monoxide and hydrocarbon emissions.

Equally significant is the treatment of the tailpipe emissions. The system comprises a metallic oxidation catalytic converter offering lower pressure loss compared to a ceramic system, and an exothermic catalyst and a catalytic diesel particulate filter (DPF) in the same container. The latter arrangement works in conjunction with a seventh fuel injector that is positioned in the exhaust.

This is activated while the particulate filter is being regenerated, a process of which the driver is completely unaware, but significantly means the opportunity for unburnt fuel to pollute the engine oil is removed. It also allows the filter to be regenerated in low-load conditions, such as idling, and therefore achieves a high efficiency level under all driving conditions. It also helps stretch oil change intervals to as much as 20,000 km for most customers.

The new engine will be available with Nissan’s advanced seven-speed automatic transmission as standard.

Stand by for a full drive impression, hopefully in the next issue of Delivery Magazine.

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