2018 Isuzu NPS 75/45-155 4x4 Auto: Review

Isuzu Trucks was understandably proud when it took the trucking media out into a state forest on the outskirts of Melbourne to show off the new NPS 75/45-155 4x4 AMT – the first ever two-pedal 4x4 light truck on the Australian market.

Since the first NPS model introduction in 1992, Isuzu’s light duty 4x4 trucks have established a solid reputation for navigating tough terrain and excelling in tight-access situations, and now the NPS with AMT is a workhorse designed for operators who want or need a two-pedal version.

The NPS is powered by Isuzu’s 4HK1 engine which is a four-cylinder 16-valve single overhead cam turbo-diesel that has a displacement of 5193cc. It’s rated at 114kW (153hp) at 2600rpm and 419Nm at 1600 to 2600rpm.

Isuzu Australia Limited (IAL) Chief Engineer, Product Strategy, Simon Humphries, said the NPS AMT has been designed to provide operators with reliability and easy manoeuvrability.

“Because the NPS with AMT is the only factory built two-pedal 4x4 light truck available on the market today, we invested the time and resources into taking a literal ground-up approach to developing a superior product for all operators looking for a 4x4 light truck that’s easier than ever to drive,” Mr Humphries said.

The big story of the new NPS is Isuzu’s MYY5T five-speed automated manual transmission, which has now been specifically calibrated for Australian off-road conditions and operations.

“The product available today was created from over three years of ongoing development and testing, much of which was conducted in Australia with teams of engineers from Isuzu Japan,” Mr Humphries said.

“Many changes were made to both hardware and software specification to ensure the best possible on and off-road driving experience in Australian conditions.

“For example, we separated the transmission fluid cooler from the radiator to increase cooling capacity in the more challenging conditions such as high ambient temperatures or prolonged operational hours in demanding terrain,” he said.

“At every stage in its development, we’ve considered how the NPS with AMT can most effectively cater to more operators looking to get behind the wheel of a no-nonsense 4x4 light truck,” Mr Humphries said.

“We’ve also included cruise control as standard across the 2018 N Series range, including the NPS with AMT, while the 7500kg GVM vehicle can be de-rated to 4500kg and driven on a car licence.

Mr Humphries said the truck’s engineering was tailored to best address the needs of organisations that may have multiple drivers for the one truck.“The approach we’ve taken has been straightforward: build it on reliable technology that helps an operator do their job more effectively,” he said.

“We’ve identified a lack of automated manual transmission options in the 4x4 light truck market and believe the new NPS will be of great appeal to operators looking for a truck that will allow multiple drivers – even those less familiar with trucks, such as bush fire brigade volunteers – to get behind the wheel.”

At the launch, we got to test out the entire range of new N-Series with a drive program that took us through the outskirts of Melbourne and then onto an off-road section where we really got to put the NPS 4x4 through its paces.

Part of our drive was through typical bush tracks and part included a disused quarry which really put the NPS into the terrain for which it’s designed. Steep ascents and descents, loose shale surfaces, even a nice bog hole to play in.

The trucks were loaded with a variety of materials including cement blocks, spare parts in the Service Packs, even water in big tanks replicating its potential as a fire-fighting truck.
The NPS revelled in the conditions and proved that it is fit for purpose as a 4x4 load-hauler.

Isuzu has specified the new NPS with different tyres. It now comes with Bridgestone L330 225/80R17.5 offering an improved off-road tread pattern for improved results on sand and mud.

We were told at the launch that the higher load capacity of the L330 tyre will also maximise use of the 3100kg steer axle limit, allowing an additional 200kg.

Certainly, the tyres proved capable on our drive and provided excellent grip in all conditions.

But it was the new transmission that we were there to test and it came through better than expected. Being an automated manual, it has virtually the same ratios as the manual version with the result being excellent engine braking and climbing ability.

The transfer case in the 4x4 auto has a low range of 1.842 and this, along with the 5.315 first-gear ratio and the final drive ratio of 5.571 gives final reduction in low-range first gear of very healthy 54.54:1.

This gives great retardation when descending steep terrain and I found we could idle down hills without need to use the service brakes – the ideal situation for serious off-roading.

One of the features of this transmission is that once 4x4 low-range has been selected, the AMT reverts to clutch-less manual control mode. This keeps the selected gear engaged and makes for extremely safe operation in a range of different conditions.

Basically, it won’t run away on you on steep descents, which is a great safety measure and means that if the driver is not that experienced, he or she shouldn’t get into too much trouble.

Shifting is a simple matter of slipping the stubby gear lever forward or aft – it really is a slick gearbox that gets the power down effortlessly, and just so simple to use. Despite being loaded, the NPS had no problem with any of the tracks we took it up (or down).

Vision from the cab is excellent with big windscreen and fabulous wing mirrors that give a great view behind.

All the major controls fall easily to hand and the interior is basically the same as a two-wheel drive N Series.

Isuzu has a history of innovation in the Australian trucking industry and has achieved 29 consecutive years of market leadership on the back of pioneering products that help operators do business more effectively.

IAL Director and Chief Operating Officer, Andrew Harbison, said Isuzu engineers were acutely aware of this legacy during the development of this latest model.

“Over the years, our NPS 4x4 trucks have served invaluable roles in emergency services fleets, especially in Australian fire brigades.

“These are operators who need the utmost confidence in the reliability, safety and access of their vehicles,” Mr Harbison said.

“We’ve developed a product in the NPS with AMT that will provide these benefits in a vehicle that more volunteers can get behind the wheel of – a considerable benefit when volunteer numbers are forever in mind for rural fire fighting brigades in particular.

“This is a truck that will provide considerable benefits to Australian operators. The NPS with AMT stands out from the field of 4x4 light trucks with its ease of operation, locally-developed improvements and application-specific engineering,” Mr Harbison said.

Isuzu NPS 74/45-155 AMT
Engine: 4HK1-TCN
Type: Four-cylinder 16 valve SOHC
Displacement: 5193cc
Compression ratio: 17.5:1
Bore x Stroke: 115mm x 125mm
Max power: 114kW (153hp) at 2600rpm
Max torque: 419Nm (309 lb.ft) at 1600 to 2600rpm
Transmission: Five-speed automated manual (AMT)
Suspension front: Single stage multi-leaf springs hydraulic dampers, stabiliser bar
Suspension rear: Multi-leaf main spring, helper spring hydraulic dampers
Brakes: Front and rear drum hydraulic, ABS, park brake on rear of transmission
Steering: Power assisted recirculating ball steering
Turning circle: 12 metres
Wheels: 17.5 x 6.00 six stud steel
Tyres: 225/80R17.5 123/122L Bridgestone L330 Tubeless
Fuel: 140 litres
GVM: 4500/7500kg
GCM: 8000/11,000kg