Isuzu Giga Tractor E-Series: Heightened thrills and capabilities

By Ghaith Madadha - Oct 30,2017 - Last updated at Oct 30,2017

Photo courtesy of Isuzu

Unlike any other experience in 15-years as a motoring writer, driving a fully-loaded Isuzu Giga E-Series articulated lorry — or tractor trailer in US-speak — through a 42° banked corner ranks right up there with the top-end supercars and luxury cars.

Entering the carousel-like bank at 110km/h while seated nearly a story high with a gross combined mass of 40-tonnes for the first time gave one pause for thought by mid-corner, when glancing at the flat tarmac a couple of lanes to the left and the sky directly above from the right side window.

Pause for thought

Captured by a brave photographer standing by the side of the road, as the second lesser bank straightened up before the giant 14-wheeler zoomed past and compressed the air in its wake, the Giga E-Series test drive was a brief but most memorable experience. The highlight of a visit that took in visits to Isuzu’s 170,000 production capacity, 1-million square-metre large and quality control-obsessed Fujisawa plant, the Isuzu Plaza Museum in Hokkaido tracing the brand’s heritage to 1916, and a practical eco-driving tutorial, the E-series test drive included three laps of the second longest 4.4km circuit at Isuzu’s proving ground towing both fully-loaded and empty trailers.

A different experience but thrill not too far removed from driving a supercar at over twice that speed on circuit, the E-Series test drive gave one opportunity to better understand the nuance need for care, and vast forces associated with trucks of this size and weight.

With both the thrill and tension undoubtedly heightened by circumstance as the test drive visit to Isuzu’s WAcom proving grounds in Hokkaido was bookended by a North Korean ballistic missile test firing above and anticipated landfall of Typhoon Talim on the northern Japanese island, one had newfound appreciation for both truck making and driving.

Heavy hauling

Thoroughly engineered and built for heavy duty use, the Giga E-Series also looks the rugged and tough machine, with an imposingly towering 3235mm high flat face cab. Measuring 2,490mm wide the Giga EXD52BD-X4NR-D 3A production code tractor version driven features two enormous 295/80R22.5 front tires and four 275/80R22.5 rear tyres on a single axle, with two to each side.

Comparatively short at 5610mm, its rear axle sits at the end of a 3180mm wheelbase, while its cabin sits atop and slightly ahead of the front axle, and offers a commanding driving position with excellent front visibility.

Weighing in at 7100kg as a tractor, the E-Series can accommodate a payload of 11,500kg and haul far more with a variety of boxed, flat and other trailer beds available. Powered by and enormous turbocharged and intercooled 15.7-litre straight six-cylinder diesel engine the E-Series’ total GCM weight rating including vehicle, payload and trailer is a vast 39,940kg.

Channelling its enormous torque to the tractor’s driven rear axle, the E-Series can be specified with either a complex 16-speed manual gearbox with eight forward ratios split into low and high range, or a much more user-friendly 12-speed automated manual gearbox, with sequential manual mode shifting, as driven.

Gathering momentum

Unlike a car engine, the E-Series gigantic 15.7-litre engine is a unit developing a maximum 454BHP at 1700rpm, by which point it is nearing its redline rev limit. With power and momentum building up slowly over 12-gear ratios to eke out every last drop of potential, the E-Series — like all heavy duty trucks — relies more on torque, which in this case is a deep and vast reservoir of 1664lb/ft delivered over a 900-1300rpm range, during which it is at its most muscular for pulling huge loads, and at which point it is most efficient to up-shift into the next gear.

Setting off eagerly from standstill, one needs to gently feed the throttle rather than slamming it down to avoid rocking its huge mass on its ultra rugged air sprung live axle and leaf spring suspension.

Unloaded by towing a trailer, the E-Series was sprightlier — if it can be described as such — and was quicker and easier accumulating speeds of 100-120km/h. However, with a full-load, progress was expectedly more laboured and timely as it gathered momentum, but became more responsive and flexible once highway speeds were achieved, which gave one a perspective on how much further planning is required for driving trucks than smaller, quicker and lighter cars.

High and mighty

Driving on a huge, empty and dedicated circuit at WAcom, one got familiar with the Giga’s size, weight and rate of progress fairly quickly. On public roads, its huge size and mass would requires far more planning, foresight, patience and skill for even the simplest manoeure, let alone more precise and complicated maneuvers, like reversing, which with a trailer and limited rear visibility, is counter intuitive. Driving at speed at WAcom one found the E-series highly-assisted ABS drum brakes most reassuringly capable and steering no heavier than a family saloon. For smoothest results, one should brake gradually to full stop, while steering is smooth but vague in feel and obviously requires more lock input.

Climbing up some six feet to enter its cavernous cabin, one sits like at a dining table atop an air sprung seat and at the very front of the cabin for good front and driver’s side visibility. Cabin height and width is enormous for three occupants, while the driver sits up close to the pedals and large slightly tilt-adjustable but almost horizontal steering wheel.

Well equipped inside, the E-Series can also be specified with a rear driver’s bunk for overnight journeys, while standard and optional driver assistance systems include rollover warning, sophisticated electronic vehicle attitude system, blind spot and lane departure warnings, and camera and radar based pre-collision braking system.

TECHNICAL SPECIFICATIONS

Engine: 15.7-litre, common-rail injection, turbo-diesel, in-line 6-cylinders

Bore x stroke: 147 x 154mm

Gearbox: 12-speed automated manual, rear-wheel-drive

Final drive: 2.866:1

Power, BHP (PS) [kW]: 454 (460) [338] @1700rpm

Specific power: 28.9BHP/litre

Power-to-weight: 63.9BHP/tonne

Torque, lb/ft (Nm): 1664 (2256) @900-1300rpm

Specific torque: 143.8Nm/litre

Torque-to-weight: 317.7Nm/tonne

Length: 5610mm