Saving Graces: Cutting the cost of consumables

By: Rob McKay

Consuming consumables is a cost transport companies want to reduce and many are keen to help them with it

Saving Graces: Cutting the cost of consumables
Fuel is a major expense for trucking companies


Spending on diesel and the lubricants that ease commercial vehicles along their paths is viewed as an unavoidable evil by their owners and one they wish to reduce where possible.

But the task has gained a sense of increased urgency recently after a period of relatively low prices.

Two years ago, the price of crude oil fell further than during the depths of the Global Financial Crisis.

On February 9, 2016, West Texas Intermediate reached US$27.94 a barrel, more than 3 cents down on December 10, 2008’s US$31.10.

Around GFC time, a decade ago, diesel was at a national average price of $A1.41 a litre, before plunging 14 cents the next year, and followed the oil price down two years ago to A$1.23 a litre.

According to the Australian Institute of Petroleum, it was recently at about A$1.30.

If the trend remains similar, oil and diesel will stay on an upward path, mirroring an economic resurgence that has also seen new truck demand burgeoning and with only a dark trade-war cloud marring the blue skies.

Few costs focus trucking minds quite as strongly as fuel prices, though the highs have never seemed to last quite long enough for alternative fuels to become entrenched.

The rise of electric propulsion looks unstoppable... in time.

"Reduced consumption of diesel fuel is good business," Linfox executive chairman Peter Fox says.

But while Linfox has been wedded to the search for alternative propulsion sources for a long time, like most of the Australian trucking industry it expects be using diesel engines in the medium-to-long term.

Scania's New Truck Generation G 500 and R 620 on the road

Turning back the tap

Unlike some other outgoings, fuel consumption is, to a certain extent, a universally controllable cost for transport companies, a common pursuit in almost all advanced industrialised countries.

It is one that major truck manufacturers are keen to impress customers with and winning awards always helps.

So it is that Scania has hailed its victory of its R 500 in the March German Green Truck Award focused on low fuel consumption.

The ‘new generation’ R 500 prime mover was armed with an updated 13-litre engine for the test overseen by German truck magazines.

It backed up on last year’s R 450 win in the same contest.

Scania says that with an average fuel consumption of 24.92 litre/100 km and an average speed of 79.91 km/h on the same 350km long test track, the difference between Scania and the next best competitor was 0.4 litres per 100 km.

It adds that the difference adds up to 600 litres annually.

All together now

Two main focuses of fuel burn reduction are on the vehicle and the driver.

In a truck, the whole vehicle can be the sum of its energy efficient parts, with the engine the most high-profile of these, as that is where the fuel is destined, but with rest, from transmission to tyres, also contributing.

It seems that almost every part and, indeed, every engine part has a part to play.

This view was driven home in Australia with Scania’s new generation trucks making their official Australian launch debut this year.

Fuel efficiency in its updated engine range — 9-litre 5-cylinder, 13-litre 6-cylinder and 16-litre V8 engines are all available in Euro 6 and Euro 5 compliance — amongst the biggest headline points.

Among the changes are a reworked combustion chamber and new injectors, producing a saving of 0.2-0.5 per cent, the company says.

A generally higher working temperature and thermostatic oil cooling contribute to additional savings, together with cooling fans, which in some cases have a larger diameter, being now directly driven without energy-intensive gearing, Scania says.

This can contribute a fuel saving of up to 1 per cent, due to the oil being kept at optimum temperature, even at lower power outputs and at low outdoor temperatures.

"In addition to the engine changes, customers can expect savings of another couple of percent," Scania Trucks product management vice president Björn Fahlström said at the event.

"A great deal of care has gone into elements such as aerodynamics and smart engine management. Compared to the just superseded Scania Streamline – our extremely efficient long-haul trucks with Euro 6 engines – the (comparable) reduction is in the region of 5 per cent.

"For a typical long-haul truck that covers 150,000 km a year, this means a reduction of just over 2000 litres of diesel and considerably lowers fuel costs."

Three of the engines, the 730 version being the exception, use Selective Catalytic Reduction (SCR) only for the after-treatment of exhaust gases means that the V8 engines now have a fixed geometry turbo unit.

"The maximum pressure for the fuel distribution system is now lower at 1,800 bar, due to the use of SCR technology for after-treatment, Scania says.

"Once the fuel arrives in the cylinders via the newly developed injection system, helped by an XPI high-pressure pump that has just two pistons, increased compression and a maximum cylinder pressure as high as 210 bar are applied – important features for reduced fuel consumption."

Scania says its V8 engine’s 7-10 per cent fuel consumption improvements are achieved via:

  • Internal changes involving increased compression, higher cylinder pressure, reduced friction, etc. (1.5-2.0 per cent)
  • shift from EGR/SCR to SCR only and a fixed geometry turbo provides higher efficiency and maintains exhaust temperatures so that requirements for raising the temperature are reduced (1.5 per cent)
  • new after-treatment system provides improved AdBlue vaporisation performance, optimised after-treatment of substrates, and less pressure loss (about 1.5 per cent)
  • new disengageable auxiliary systems ( 1.5 to 2 per cent for customers with "normal, representative driving patterns")
  • Aerodynamic changes that initially came with Scania’s New Truck Generation (roughly 2 per cent for typical long-distance customers "even with Australian specification bull bars fitted, as proven by in-country testing").
Scania's new generation engines use technologies new and old to increase efficiency

Miller Camshaft

Interestingly, Scania has gone back to the future in its search for savings.

Like the other 6-cylinder engines, the new 370 hp engine has undergone a complete upgrade, with a new engine management system and reworked cylinder heads. It also now relies on a fixed geometry turbocharger and SCR only.

In addition to these improvements, which themselves lower fuel consumption by about 4 per cent under typical driving conditions, the new configuration of the engine has been equipped with a Miller camshaft.

Scania argues that Euro 6 engines with a large displacement and relatively low power output run a certain risk of having problems with after-treatment because the engine doesn’t naturally generate enough of the excess heat that is required to maintain a sufficiently high temperature in the after-treatment system.

"One solution to that problem can be to burn extra fuel when required, which of course increases fuel consumption," it says.

"Scania’s solution is more elegant. The engine instead operates according to the Miller cycle, a technology patented in the United States in the 1950s.

"Using a special profile on the camshaft for the intake valves keeps them open a little longer than normal during the compression phase.

"That means less air is pumped through the engine, which contributes to keeping the temperature up and the SCR system running – all without the need to add diesel for the sake of heat alone."

AirFlow Starship

This is not so say OEMs are doing it all by themselves. In the US, one of the more fascinating collaborations is between Shell Lubricants and the AirFlow Truck Company and here again; the various components’ ability to be part of the fuel-reduction process comes to the fore.

The AirFlow Starship, complete with solar panels on the trailer roof and ultra-aerodynamic carbon-fibre prime mover design, has been tested to see how advances in engine and drive train technology, the use of low viscosity synthetic lubricants, aerodynamic designs, efficient driving methods and more can come together.

It uses last year’s Cummins X15 Efficiency six-pot to put 298Kw (400hp) and 2508Nm (1850ft lb) to the task.

Shell has aimed its Rotella line of engine oils and lubricants at the project, including it fully synthetic heavy duty engine oil, its diesel exhaust fluid and extended life coolant.

Also in that mix are the Spirax range including the, S6 GXME  75W-80 transmission oil, S5 ADE 75W-85 differential oil and S6 GME 40 wheel hub oil.

Beyond the active grill shutters, use of which is based on temperature to maximise aerodynamics, and the trailer’s boat tail end for streamlined air flow around truck and drag reduction, other efficiency items include:

  • hybrid electric axle system for a power boost while climbing grades
  • custom automatic tire inflation system for consistent tire pressure and optimal fuel economy
  • downspeed axle configuration provides improved efficiency and pulling power
  • 5000Watt solar array charges and stores power for normal electrical components.

"The energy transition will play out over many years and it seems unlikely that any ‘silver bullet’ solution will emerge," Shell Lubricants technology manager for innovation Bob Mainwaring says.

"In that sense, it’s useful to work out just how good we can be today if we draw together the most promising efficiency concepts into a single place… in effect being the best we can be every day."

You can find another image of the test vehicle in this edition’s Mid-America Trucking Show feature.

The Airflow Starship shows the lengths Shell Lubricants will go to to prove a point

Driver training

It is a sometimes overlooked truth that the importance of driver behaviour to efficient driving was recognised decades before OEMs made driver training a central part of their auxiliary service offerings.

Of course, amongst the OEMs taking driver training most seriously is Volvo and the Volvo Fuel Challenge is followed in ATN as much as anywhere.

Efficient driving first came into vogue in the early 1970s with the first oil price shock.

In 1989, John Saunders and Peter Thompson produced the Truck Drivers Manual for the Federal Office of Road Safety, saying :"Australian and oversees experience has shown that proper training of truck drivers significantly reduces vehicle maintenance costs (by almost half in some instances) and improves fuel economy."

Much of the advice over the years has been common-sense items.

In 2009, the Australian Trucking Association noted in its Trucking Industry Environmental Best Practice Guide that trials undertaken in Sydney by two large transport companies showed ‘smooth’ drivers used 27 per cent less fuel than ‘lead footers’ in an empty Kenworth, with only three minutes added to a 70 km run. US research found that driving aggressively increased fuel consumption by nearly 30 per cent, with only a 10 per cent increase in average speed.

The researchers offered the following advice:

  • anticipate conditions ahead so that braking is minimised
  • do not accelerate to a higher speed than required if you must later slow or stop— every time brakes are applied, energy extracted from the fuel is dissipated
  • avoid stopped delays—fuel used idling is unproductive and, when accelerating after stopping, increased energy must be extracted from the fuel.

Other research shows that performance improvements can come from:

  • starting up/warming up—start with no throttle, idle until full oil pressure is indicated, maintain low engine speed until water temperature begins to rise
  • easing up to full speed—use only enough revs to keep the truck moving and to reach the next gear smoothly
  • watching the tachometer—fuel efficiency is greater when engine speed (rpm) is slightly above where maximum torque is produced
  • downshifting—let the engine pull down to torque speed before selecting lower gear, because lower rpm means lower fuel consumption; and
  • avoiding jerky patterns of acceleration and deceleration—sudden acceleration results in incomplete fuel combustion and heavy exhaust smoke.

More recently, fleet software firm Verizon Connect vouched for this sort of advice but advocates driver education because drivers:

  • realise they can make a big difference
  • can learn that using less fuel improves both job security, by making the firm more profitable, and the environment through reduced emissions
  • are more conscious of how they drive and how it affects fuel consumption
  • understand the safety benefits of driving more responsibly.

As said, this is an international pursuit, so here are a few tips from our Kiwi cousins that may be worth a look for those whose fleets are preponderantly manual. They come from driver outfit DT Driver Training, which counts Toll, Freight Lines and Allied Pickfords amongst its clients.

  • Keep the wheels turning: use anticipation at traffic lights, roundabouts, cornering and in stop-start traffic
  • Take it easy while the engine is cold as cold engines burn more fuel.
  • Keep revs in the economical power band
  • Don’t sit with the engine idling
  • Keep the revs down
  • Use block shifting (skipping gears)
  • Keep the engine well-serviced
  • Obey the speed limit or shoot lower
  • Reduce the resistance from the air and the road
  • Make your truck as aerodynamic as possible
  • Opening the windows is better for fuel economy than air conditioning
  • Use 6×2 axles rather than 6×4 axles
  • Keep your wheels aligned and tyres properly inflated
  • Use cruise control
  • Use your momentum
  • Don’t overfill your tank
  • Check that the tank seals correctly.

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