Hard lessons

In Tests, June 201613 MinutesBy NZ Trucking magazineJune 2, 2017

Isuzu make a no-nonsense truck. They‘ve had the top selling range of trucks in the New Zealand market for 16 years in a row; however heavy-duty truck buyers are generally a demanding group and the Giga doesn‘t always fit their needs. The new model sports the highest horsepower engine available in a standard Japanese truck; an engine that meets Japan 05 emission standards through SCR, and is backed up with an all new 16-speed automated manual transmission (AMT) built by Isuzu, although the omnipresent 18-speed Eaton manual is still available. The EGR engine and AMT in the previous model were the two most criticised components and we were keen to find out if the changes have addressed the problems.

Few trucks incite as much anticipation as the latest Isuzu Giga Series. New Zealand Trucking editor of the day, Peter Lynch, visited Japan over a year ago to try out the new models (NZ Trucking, June 2015). Pete only had the opportunity to try pre-production models out on a banked test circuit, so we jumped at the chance to try one out on the very different roads of the North Island.

RJ Lincoln in Tokoroa operates a wide variety of trucks, mostly curtainsiders and tippers at up to 50 tonne. The fleet includes three older model Isuzu Gigas, all with the notorious early AMT gearbox. Lincoln‘s ordered a new 8-wheeler Giga and a 6-wheeler Isuzu F-series at the same time. Business owner Raymond Lincoln says he primarily bought the Giga because of the estimated return on investment and availability, but the relatively high horsepower, high torque SCR engine and potential benefits of the new AMT sealed the deal.

RJ Lincoln Izusu

We met the truck at Lincoln‘s depot in Tokoroa. It is a flat deck with curtains and tows a three-year-old 4-axle full trailer, operating at a maximum of 44 tonne. RJ Lincoln general manager Gavin O‘Donoghue points out that they need units shorter than 23 metres long to negotiate some of their customers‘ sites and it is intended to remain at 44 tonne, although it displays an H plate because it‘s over-length. They used a drawbar length that gave them the optimum ability to meet customer needs.

The truck carries general freight all around the North Island; when we arrived it was loaded with pallets of bagged fertiliser for rural supply stores in the Bay of Plenty. Lincolns carry a lot of sawn timber and the truck probably carries more of that than other product; on the day it is expected to backload timber from Kawerau after dropping the fertiliser.

It‘s a smart looking truck; it‘s clear that RJ Lincoln wouldn‘t settle for the basic package. The high-roof cab is topped off with a tight-fitting air kit and side extenders flow back to meet the Roadmaster body. But it‘s the scrollwork that stands out to a traditional truck enthusiast. Many operators have moved away from scrollwork, but Raymond remains a staunch supporter of the artful tradition. The truck‘s signage is by Cliff Mannington at Signwork, so the level of creativity is much higher than that expected in a run-of-the-mill fleet truck; Cliff ‘s talent is evident not only in the scrolls, but also in the truck number on the vents, the flames on the grille panel, the finish on the side stripes as they terminate on the side extenders, and the two-colour arrow graphic on the air kit.

The cab is noticeably higher than the earlier model but it‘s an easy climb with great grab handles. The cab‘s large and the high-roof sleeper is clearly suitable for overnighting, with a full privacy curtain fitted. Even with the high interior height, the almost knee-high engine cover dominates the cab, although there‘s plenty of legroom.

The engine has been upgraded with SCR added to control emissions. It‘s equipped with a 75-litre DEF tank and a 400litre fuel tank. Zane says the DEF lasts two to three days between top ups, but the fuel tank can need to be refilled before his workday is completed. On the road the engine responds well, it‘s smooth, quiet and well behaved, although under acceleration and on steep hill work we would describe it as more comfortable than aggressive, probably an ideal fleet truck characteristic.

Dashboard IzusuThe AMT, on the other hand, is all-new; it‘s called the Smoother-G transmission and is packed with features. Zane has been experimenting with it in manual, but in full auto it performs extremely well. It usually changes up at about 1500rpm on the flat and at 1700rpm on hills. In auto it will skip gears when the skip gear mode is used, but the AMT is smart enough to make single gear-shifts when conditions warrant, and there is a skip gear button that makes it change two gears when in manual. On the road we didn‘t pick up any performance issues with the Smoother-G.

Another button is used to select either power or economy mode. Power mode does not simply hold the transmission in a gear until the engine revs out to maximum horsepower; the Smoother-G is smarter than that. Isuzu point out in their manual: “When in ECON mode, the optimal gear is automatically selected based on road gradient, vehicle speed, engine speed cargo weight and engine load. When in POWER mode, the gear is selected based on accelerator opening degree and vehicle speed.” The transmission also has Smart Glide, an optional technology that slips it into neutral when coasting on long flat sections of road. It‘s potentially a great fuel saver and is well known to drivers of Volvo Group trucks who have similar technology available to them in some I-Shift variants. There are a number of criteria that must be met for Smart Glide to activate to ensure the truck is safe when rolling in neutral.

Another feature of the Smoother-G is that upshifts occur at higher engine revs when the truck is travelling slower than 30kph and the indicator switch is turned on. This effectively gives the driver faster acceleration in situations such as moving out of side roads on to highways and is ideal when Zane pulls out of Lincoln‘s yard onto SH1. The cruise control is also linked to both the retarder and the AMT. When a speed is set, the exhaust brake and retarder will automatically apply when necessary to control the speed on descents and the transmission will automatically shift to an appropriate gear.

Unlike most AMTs, the Isuzu has a clutch pedal; it‘s there for slow speed manoeuvring. AMTs usually don‘t move when a gear is selected, they move when the accelerator is depressed. In tight situations, the truck can jerk forward (or backwards if reverse is selected) a short distance before the driver has a chance to respond by touching the brake. This can make it difficult when reversing up a slope or turning in confinedareas. Using the clutch pedal provides the same advantage of feathering the clutch as a manual ransmission and allows the driver to keep the truck‘s movements under control.

We head south to Reporoa where the first delivery will be made. Zane takes some back roads and explains how well the truck handles on the narrow winding roads, but he is disappointed in the ride over the bumpy sections and it is noticeable from the passenger‘s seat.

At Reporoa some pallets are forked off the trailer at a rural supply store. Zane takes the truck around the back of the building to reach the exit and points out that the steering lock is great. Even with the tight lock, it‘s clear that a longer trailer would mean moving some cars to get around the back of the building.

A smart feature is a camera that shows the tow coupling when reversing. It not only helps line up the towing eye, but also allows the driver see when the pin drops. It‘s a small advantage, but the type of innovation we see creeping into the transport industry with improved technology.

The next run is through to Galatea and on the long flat sections of highway near Kaingaroa the Smart Glide kicks in, notifying Zane with a light on the dash when it‘s activated. He controls road speed via the retarder on the drop down the 14 Mile Hill into Murupara. The unit is down to about 35 tonne at this point and makes the descent comfortably at 90kph. Zane pulls the retarder lever down two stages and touches the accelerator pedal when the retarder slows the truck too much.

He is impressed with the retarder and says it performs better than the Renault‘s one. The two-stage lever engages the exhaust brake (X-Tard in Isuzu speak) in stage one and brings in the permanent magnetic driveshaft retarder (Giga-Tard in Isuzu speak) in stage two. In auto with the cruise control set, the transmission will downshift one or two gears when the exhaust brake and magnetic retarder are applied. The system is effective and the Giga-Tard is silent.

The truck handles narrow rural roads well, but bumps and bridge approaches are noticeable in the cab.

After offloading more pallets of fertiliser at Galatea, we follow the Rangitaiki River downstream and cross the Matahina Dam before dropping another few pallets at Edgecumbe. The truck handles the winding road comfortably. The tapered roller drum brakes are smooth and apply consistently when Zane touches the footbrake. The final load is for a Farmlands store in Whakatane. There‘s nowhere convenient to leave the empty trailer, so Zane takes it into town. It‘s a tight fit getting into the store; there are plenty of cars around, but Zane reverses the Isuzu and trailer in neatly. Getting out is just as awkward, but the Isuzu and its driver have all the resources to do it easily.

As Zane drives the truck to Kawerau to pick up a load of sawn timber destined for the Waikato, we reflect that it‘s clear that the rig‘s size and attributes are ideal for the role it plays in Lincoln‘s fleet. While it will be sometime before the Isuzu‘s whole of life cost can be estimated with accuracy – it‘s looking good so far.