Saving fuel and CO2 emissions from construction equipment is a factor that is gaining increasing focus in the mining industry. That’s why a team of American researchers has been researching how engine loading can save fuel on bulldozers. They state that several of the results are likely to be transferable to wheel loaders as well.

Let’s start with the exciting stuff:

The results

The researchers conclude: By reducing the load factor of the engine by 15%, you can save fuel worth £201 per hour and just over £1 million per year. This is for a single machine.

But that calculation is based on 5,200 operating hours per year. Fortunately, few people in Norway have continuous 24-hour operation, and we also get 5 weeks of vacation.

In addition, diesel costs slightly more in Norway.

Diesel prices as of February 24, 2020:

  • Norway = NOK 8.5 (tax-free diesel ex. VAT)
  • USA = 7.3 kroner

Diesel in Norway is 4. most expensive in the world right now

If we factor in a 16% increase in the price of diesel and assume a full-time equivalent of 1,695 hours, we find that you can save fuel equivalent to NOK 396,705 per year.

Other figures:

  • 11% higher fuel efficiency by dosing from the front of the dose area instead of the back-to-front method
  • Switching from high idle to low idle for 30 minutes a day saves fuel consumption by 1,710 liters a year
  • Turning off the engine instead of using low idle for an hour a day saves fuel consumption by 2,430 liters a year
  • Dosing material with a downward gradient gives great savings over time, how much depends on the gradient

Other factors that affect consumption:

  • operator skill
  • bulldozer power
  • fuel quality
  • outdoor temperature
  • adequate maintenance

Good management of the above factors can reduce fuel consumption without significant investment or operational changes.

This is what’s interesting: Without significant investment.

Below is a suggestion on how you can implement the savings in your organization over the next few months.

The numbers behind the survey

For the purpose of this study, a selection of six Caterpillar bulldozer models was chosen.

Hourly and annual costs for different load factors were calculated assuming that the unit cost of fuel was NOK 7.59 per liter and 5,200 operating hours per year.

According to Caterpillar, an engine that continuously produces full rated power operates with a load factor of 100%. It can reach 100% load factor occasionally, but rarely operates at this level for extended periods. Periods spent idling, driving in reverse, driving empty, tight maneuvering at partial throttle and operating downhill are examples of conditions that reduce the load factor.

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We’ve previously written that drivers are the most important people in a crushing plant, as the way they load affects the entire crushing and screening process going forward.

Here you can see how much impact they can also have on your bottom line:

The results in Fig. 2 indicates that fuel consumption is a linear function of the load factor. However, fuel consumption increases faster in absolute values for larger bulldozers. It can also be observed that the increase in fuel consumption for the smallest bulldozer (D6R) is 6.1 liters per hour for every 15% increase in the load factor. The largest model (D11R) has an increase in fuel consumption of 26 liters per hour for every 15% increase in load.

According to the results shown in Fig. 3, the hourly costs for the largest bulldozer (D11R) range from NOK 463 at a load factor of 35% to NOK 110 at a load factor of 80%.

According to the results shown in Fig. 3, the annual costs for the same bulldozer range from NOK 2,406,938 (LF = 35%) to NOK 5,504,393 (LF = 80%).

By reducing the load factor by 15%, a saving of NOK 201 per hour and NOK 1,045,637 per year can be achieved. This is for a single bulldozer.

Read more:
Why drivers are the most important people in crushing plants

How to save fuel on construction equipment

In the words of the researchers: there is a strong correlation between power and engine load factor.

Okay, it’s established. Scientists agree, but what do we do about it?

Wheel loader that transports loads.

18. March is International Drivers’ Day. It can be a good opportunity to have a small gathering and professional day. Combination between environmental creation and useful facts. Set aside 2 hours after lunch, buy a cake, create a celebration and show your appreciation for your drivers.

In addition to a positive workplace atmosphere, people are more open and receptive to new ideas when they feel valued. It’s important to start with celebration and environment building, as change, ideas, thoughts and rules from management are not always well received.

Only when everyone is happy and satisfied can you consider having a presentation with facts and dialog. Feel free to use the fuel consumption figures above if you wish.

Makes value creation visible

Making value creation visible is traditionally a motivating factor for improvement. Maybe you can keep track of how much fuel you use per year and see if it goes down?

Presenting total fuel consumption on a month-by-month or quarterly basis can have a positive effect. But remember to take into account that lower temperatures increase consumption.

Here, too, are some tips that can be discussed:
Why drivers are the most important people in crushing plants

The sum of this shows the impact and importance of the driver’s job.

NB: In many cases, it can be counterproductive to create specific rules or guidelines, e.g. from now on, everyone should load in a specific way. As a result, drivers often get the feeling that management is holding things over their heads.

It can be far more effective to present the numbers and importance objectively, then let it sink in with the individual over the next few weeks, and run a new focus round where you listen to their feedback in a few months.

Whether you want to take action on fuel consumption or not, remember that drivers are worth their weight in gold. Give them a little celebration on March 18.


Spreadsheet to lost production