Trucks

Isuzu Enhances its Flagship Giga Range

Isuzu Giga under test in Japan, complete with an Aussie-spec B-double set

In an obvious bid to bolster its credentials in the big end of the business, market leader Isuzu has enhanced its flagship Giga range with a number of updates aimed at ‘delivering better fuel economy and an improved driving experience’. But as STEVE BROOKS asks, will it be enough to notch bigger numbers?

Top ‘n’ Tail

With 23 years of continuous market leadership now seemingly as certain as tomorrow’s sunrise, it’d be reasonable to think the folk at Isuzu Australia would be fundamentally content with the company’s unrivalled achievements over so many years. And for the most part, they probably are.

Yet despite the phenomenal longevity of Isuzu’s reign at the top of the tree and the obvious satisfaction and pride this brings, company principals have bluntly stated many times over that there’s no room for complacency or weakness, nor blindness to windows of opportunity.

The same principals, however, have also been known to quietly concede to a weak link in the Isuzu armour; one which has existed for many years, subsequently denying the company the ability to meet the full gambit of Australian operations. Perhaps worst of all though, particularly for a highly professional outfit ultimately responsible for its own extraordinary success, it appears there’s not a great deal Isuzu Australia can do about it.

Obviously enough, that weak link is in the top tier of the heavy-duty market where Isuzu competes with its flagship Giga range. On the surface it may seem an odd weakness, given that along with being the entrenched master of the light and medium-duty classes, Isuzu is also the leading Japanese brand in the heavy-duty class and in recent years has gained considerable ground, occasionally surpassing the likes of Freightliner and Mack. However, the bulk of Isuzu’s growth in the heavy-duty arena has come from an expanded range of high-end F-series rigid models rather than galloping demand for Giga.

So despite the fact that Isuzu’s 510 hp Gigamax flagship is the highest powered Japanese truck on the market, why does Giga struggle when its smaller siblings are so remarkably successful?

There are, it seems, several answers. For starters, Isuzu’s lighter models predominantly compete against other Japanese brands in market segments which over many decades have become completely reliant on Japanese trucks. Giga, on the other hand, is battling for recognition in a field where the world’s biggest brands come to play, and play hard. What’s more, it’s a field where Isuzu’s competitive countrymen also have strong ambitions and in a somewhat strange twist, the leading Japanese seller of trucks above 350 hp is actually the least prolific of all Japanese brands on the Australian market … UD!

More to the point though is the fact that Giga is a truck essentially designed and built for the Japanese domestic market and its Asian neighbours. So too, of course, are top weight Fuso, Hino and UD models also made for much the same markets. The result is trucks of immense structural strength but largely lacking the broad appeal of their American and European peers, and subsequently struggling to achieve strong sales volumes.

It’s obviously a different story in the lighter classes where vastly expanded export goals have seen all Japanese brands throw huge resources into the development of new cabs, engines and drivetrains for light and medium-duty models competing on domestic and export markets. The downside to that, however, is that Japanese development of heavy-duty models for advanced, mature and highly competitive export markets such as Australia has in many cases simmered on the backburner.

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This was a point cautiously conceded late last year by Yoshinori Ida, the astute corporate heavyweight who over the course of the decade directed Isuzu’s return from the rim of ruin. In an exclusive interview with DIESEL, Ida-san confirmed the fundamental differences between Japanese and western requirements for heavy-duty trucks make it difficult to be all things to all people. Equally though, he agreed “something needs to be done” but was short on commitment when asked about eight-wheeler derivatives of Giga and more critically, if an advanced new engine of, say, 13 litres displacement was being developed to replace the 15.7 litre lump which some – including us – see as the greatest single detriment to Giga’s potential in markets such as Australia. “Not yet” was Ida-san’s blunt response on both topics.

There are, of course, those who will justifiably argue that a big cube engine dispensing modest outputs will live longer than a smaller engine punching the same or even bigger performance. Technology and fuel prices have, however, done much to quash that argument.

Thus, in a modern heavy-duty world where advanced 13 litre engines are fuel efficient, powerful and popular, Isuzu Australia appears stuck with the 15.7 litre engine which in all versions except the 510 hp Gigamax delivers peak power of just 338 kW, or 450 hp. Yet even at the top 510 rating, it’s not much muscle for an engine of such copious capacity.

Nor is peak torque of 2255 Nm (1663 lb ft) in all ratings particularly inspiring from such a hefty piece of hardware; and even less inspiring when measured against UD’s top GW470 model which plucks the same amount of torque from a 13 litre placement. But the heavy Isuzu engine takes an even bigger beating when lined up against the top rating of Volvo’s 13 litre six cylinder engine, delivering a brawny 397 kW (540 hp) and tenacious 2600 Nm (over 1900 lb ft) of torque. And this, of course, is the sort of competition Giga faces.

In the meantime, little is likely to change for Isuzu Australia until Japan develops a new heavy-duty engine in a size and form consistent with leading world technology.

Local Initiative

Typically though, Isuzu’s local leaders are striving to do the best with what they have. In fact, in an upbeat press release the company recently pronounced, ‘A series of enhancements to Isuzu’s heavy-duty Giga range is delivering operators greater fuel economy and an improved driving experience.’

According to Isuzu, ‘… engineers have undertaken two years of research and development to refine the current Giga range, offering its most attractive heavy-duty transport solution to date.

‘The result,’ the company states, ‘is up to 10 percent improvement in fuel economy across the range – depending on application – heightened driver comfort, and four new Giga variants.’

“We recognise that there’s always room for improvement,” said Isuzu Australia product planning and engineering support manager Colin White. “On the fuel economy front we’ve made several refinements to the Giga range designed to deliver a marked improvement.

“We’ve revised the engine control software of the Giga range to enhance fuel efficiency at low engine speeds, adjusted the rear axle ratios on some models to provide low RPM at cruise, and modified shift strategies in the transmission software to reduce average engine RPM.

“And the reprogrammed engine software has adjusted the ‘sweet spot’ so optimal fuel economy is reached at lower engine RPM, and over a greater operating range.

“To take advantage of this change, axle ratios were revised on some models to reach optimal fuel efficiency when cruising at 100 km/h.

“The shift points on the AMT (automated mechanical transmission) have also been adjusted downward in the engine operating range on both 12 and 16-speed models,” White explained.

Additionally, three ‘highway’ variants have been introduced to the CXY 455 18-speed and CXY 455 Premium models, fitted with Michelin Energy Tyres to reduce rolling resistance and fuel consumption while minimising cabin noise, the company states.

Additionally, the flagship Gigamax model is now being offered in a ‘general purpose’ variant known as the EXY 510 GP, said to be engineered to deliver greater fuel economy in single-trailer and B-double applications due to the reduced axle ratio and Michelin Energy Tyres.

Furthermore, Isuzu advocates the use of a range of aerodynamic accessories to reduce drag and fuel consumption.

“We always recommend that operators consider adding the full complement of aerodynamic accessories to their Gigas as this can reduce drag by up to 15 per cent and deliver significant fuel savings,” Colin White concluded.

For now and perhaps several years to come, Isuzu Australia will obviously continue to make the most of what Giga offers. Eventually though, Japan must bite the bullet on heavy-duty engine development before its highly successful Australian offshoot can hope to be little more than a bit player in the big end of the business.

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