The fuel efficiency drive for wheeled loaders
By Chris Sleight10 September 2013
Wheeled loaders built for the European Union, Japanese or US markets now feature engines with very low emission levels. And laws are due to get tighter. The current Stage IIIB, Tier 4 and Tier 4 Interim legislation (respectively for each territory) will be replaced next year with even tighter requirements.
These will see exhaust gasses having about the same level of pollutants in them as the ambient air in many cities. In fact, some manufacturers say that when Tier 4 Final and its equivalents are in place, their machines will act as air cleaners in some places.
Many parts of the world have similar but less stringent regulations to cover wheeled loaders and other types of construction equipment. They include developed countries like Australia and South Korea as well as major emerging markets like Brazil, China, India, Russia and Turkey.
Elsewhere in the world, including other parts of Latin America, Eastern Europe, Africa, the Middle East, South-East Asia and the CIS excluding Russia, regulations lag further behind or there are no laws at all to restrict pollution from off-highway equipment.
This is a headache for wheeled loader manufacturers, who, in an ideal world, would make one base machine with the same engine in it to cover all global markets. Instead they need at least two parallel lines – one for highly regulated countries and one for lesser regulated ones. Some even say there is a case for three ranges – highly regulated, lower regulation and zero regulation markets.
There are several reasons for this. The first is that machines built for Europe, Japan or the US have a lot of expensive technology on-board to cut emissions. It is doubtful such a price premium would be accepted in countries where it was not legally required.
Arguably more significant though is the issue of fuel quality. In order to run correctly, the current crop of Tier 4 Interim or equivalent wheeled loaders need ultra low sulphur diesel (ULSD), meaning around 15 parts per million (ppm) of sulphur.
Higher levels of sulphur would lead to greater amounts of particulate matter (PM) being produced, which would block systems such as diesel particulate filers (DPFs) and selective catalytic reduction (SCR) in machines’ exhausts. This in turn would make engines overheat, break down and suffer permanent damage.
Such fuels tend not to be available to the off-highway sector outside Europe, Japan and North America, so it would be catastrophic for machine owners if loaders requiring ULSD were sold in these regions.
These global variances in engine regulations have forced manufacturers to develop and produce at least two different ranges of wheeled loaders. Although this is not what they would want in an ideal world, it is good news for machine buyers who are seeing loaders coming onto the market that are better suited to their requirements, rather than a ‘one size fits all’ approach.
Some of these differences were outlined by Marc Glesius, Doosan’s product manager for wheeled loaders in Europe.
“In the EU and US, Doosan is now offering new Tier 4 Interim or Stage IIIB machines from the new generation Dash 3 (DL-3) range running from the new DL200-3 model to the largest, the new DL550-3 wheel loader. For emerging markets, we offer two parallel lines of products – the new, mainly Tier 2 DLA range and the Chinese WLO DISD range based mainly on Tier 1 engines.
“Apart from Stage IIIB and Tier 4 Interim engine technology, the DL-3 machines are equipped with 5-gear transmissions and lock-up torque converter, load sensing hydraulics, supreme radiator technology and have many special standard features included, which are just options for other suppliers such as auto lube, cyclone separator, two-way suspended seat, heated mirrors, reversible fan, load isolation and many more. The DLA range is powered by Doosan Tier 1 and Tier 2 engines, which are not electronically controlled, to meet simplified servicing requirements in emerging markets,” he said.
“These are strong machines with outstanding torque at low revs and high class components (ZF, Parker, Kayaba, etc.). Furthermore these machines are designed to run in both tropical and high ambient temperature applications with optional axle cooling, special air breathers or radiator geometry.
“To meet market demand for very economical machines in emerging markets, Doosan is offering (as the competition does) low cost alternative wheel loaders made in China, the DISD range. The two models, designed for the Chinese market are also available as export versions with a ZF transmission, a Tier 1 Doosan engine and modifications for applications in tropical climates,” he said.
This is the same broad approach that many manufacturers are taking. Wheeled loaders for emerging markets may not have the same levels of technology on-board as those for Europe, Japan or the US, but they still have to be durable machines – perhaps more so than their developed market counterparts – and they often need to cope with much more extreme ambient temperatures and harsher work environments.
Caterpillar’s new machines for lesser regulated countries are the 986H and 988H. The 986H is an interesting one because there is not an equivalent model available in developed countries, while the 988H has its counterpart, the 988K for these territories.
Caterpillar spokesman Olivier Lefévre said the 986H with its 42 tonne operating weight was designed to fill a gap between the 31 tonne 980 and 51 tonne 988 models, although it shares some key components such as the front axle and brakes with the 988.
“There is a simple operator interface, simple technology with less electronics, but high productivity and durability,” said Mr Lefévre.
But simple technology for owners and operators – such as a Z-bar linkage and simple steering wheel control, rather than joysticks – “In lesser regulated countries people prefer a wheel,” said Mr Lefévre – belies some clever design features.
These include a cut-out areas in parts of the boom where steel is not required for structural strength, which Mr Lefévre said removed 500 kg from the front-end linkage. This saving is something that can be translated into more material in the bucket and less dead weight being carried around.
The loader is designed to match 36 to 55 tonne haulers such as the Cat 770, 772 and 773 rigid haulers. Mr Lefévre said it could load the smallest of these in four passes and the largest in five to six, but for this would need a high lift front-end to add 500 mm to the dump height.
The new 988K for highly regulated markets meanwhile weighs in at 52 tonnes and is designed to work with Cat’s 64 tonne capacity 775 rigid haulers. The company says its fuel consumption is the best in class, some -20% lower than its predecessor, the 988H. This has been achieved with a new Eco mode and tuning the hydraulic system to give its maximum flow at 1,400 rpm on the engine, rather than 1,800 rpm as was the case previously.
In a similar vein, one of JCB’s latest loaders, the 467 has been designed for lesser regulated markets, and the company says its structures should last 20,000 hours or more.
Weighing in at nearly 24 tonnes, and fitted with a 4 m3 bucket as standard, it is the largest wheeled loader the company has ever built. JCB says the pre-launch evaluation programme saw prototypes log-up thousands of hours of testing with customers, in temperatures ranging from -20°C to + 50°C.
JCB’s chief innovation and growth officer, Tim Burnhope, said, “JCB has made a substantial investment in developing the JCB 467 to ensure it provides the durability, reliability, efficiency and productivity customers for this machine demand.
“The JCB 467 has been designed from the ground up and will deliver all these attributes with the lowest possible operating costs. The 467 will initially be offered in non-emission legislated markets where we see the biggest growth potential for this size.”
The company says the optional five-speed Driveline Efficiency Package can offer fuel savings of up to -20% and productivity gains of up to +40% compared to the standard four-speed model, while it added that benchmark tests showed the 467 to be up to +25% more productive than the nearest competitive model. Power comes from a 290 hp (216 kW) 10.8 litre Cummins engine, driving a ZF transmission and axles.
Further down the scale meanwhile the 411 and 417 are its latest loaders for regulated markets, with 68 kW and 93 kW Stage IIIB engines.
These machines use both JCB’s own axles and engines, with only the transmission coming from ZF. JCB said a great advantage of this was that it had achieved Stage IIIB compliance on its own engines without the use of any exhaust aftertreatment, such as a DPF. Without this extra bulk, the machines could be kept compact and servicing and operating costs minimised for the machines’ owners.
Joint venture brand
Another key launch for lesser regulated markets has come this year from SDLG, Volvo’s Chinese joint venture. The LG953N was, like the JCB 467, launched at June’s CTT exhibition in Moscow, Russia.
The selling point of the 16.6 tonne LG953N is its low-speed powertrain, which offers better efficiency and lower fuel consumption than its predecessor. At the same time, performance and durability have been improved with new features like a reinforced drive axle. The redesigned cab offers better visibility, while air conditioning, vibration damping, a digital instrument panel and all-round seals make it a comfortable environment.
Komatsu’s latest models, both launched at April’s Bauma exhibition, are the 18 tonne WA-380-7 and 33 tonne WA500-7, which have rated engine powers of 143 kW and 263 kW respectively.
The WA380-7 would tend to be fitted with a bucket around 3.2 m3 capacity, while the WA500-7 is up in the 5.5 m3 class.
Both are for highly regulated markets, with their Tier 4 Interim/Stage IIIB engines, and are supported by Komatsu Care, a complementary maintenance programme for all Komatsu machines with this type of engine that covers the first three years of 2,000 hours, incorporating work by Komatsu-trained technicians using genuine parts.
Also included are two complementary exchanges of the DPF and a warranty on the first DPF for five years of 9,000 hours.
The Komtrax telematics system is standard, and this uses a secure website to feedback key information such as operating hours, fuel consumption, location, cautions and maintenance alerts to machine owners. It also now features details about the type of work the machine is doing, engine performance and the status of the DPF.
High capacity lock-up torque converters are standard and these are said to improve hill climbing and acceleration, while delivering a higher top speed and lower fuel consumption.
Operators meanwhile will appreciate the quiet cab environment and short lever pilot controls. New on these models is a 7 in (178 mm) high resolution screen supporting 25 languages, where settings for items such as auto idle shutdown or the auto-reversing fan can be changed.
In addition to several new models launched at Bauma, Liebherr took the wraps off a prototype version of its 32 tonne L 586 loader, the X-Power version, which uses a continuously variable power-split transmission combining mechanical and hydrostatic drivelines.
When travelling at slow speeds, the loader is driven mainly through the hydrostatic transmission, which is more efficient in this range, but as speed picks up, the influence of the mechanical drive increases. Liebherr says that this twin approach reduces transmission losses across the board and leads to a higher performance in every part of the working cycle.
Whether new loaders are destined for highly or lesser-regulated markets, the common theme remains improving fuel efficiency and performance. Different manufacturers are taking different approaches to this, be it cutting unnecessary weight, offering more sophisticated driveline packages or designing their machines around lower engine revs.