There are many reasons to reduce unnecessary idling in machine work, mainly fuel economy, engine wear and emissions. A well-informed driver can actively avoid excess idling, but also machine and engine manufacturers can build in features that promote optimal engine use. AGCO Power Account Manager Heikki Hihnala talks about both approaches.
In many kinds of machine work, the engine idles a surprisingly large percentage of its total running hours. Almost any task includes plenty of stops and breaks, all while the engine is idling. Historically, there have been reasons to avoid stopping the engine, as the batteries had smaller capacity and older diesel engines were tricky to start. But what about today?
“A well-designed modern engine does not mind continuous stopping and starting,“ Heikki Hihnala says. “Being able to reduce or slow down idling has many benefits.”
Why reduce idling?
Among the reasons to avoid idling, Heikki mentions the following:
- Reducing emissions. Engines are optimized for normal working conditions, so idling emissions are proportionally much higher.
- Reducing fuel costs. It is good to recognize that the fuel costs are the single biggest expense during the machine operating life. According to our internal research, reducing idling can cut fuel consumption by 2.4%.
- Reducing engine wear. In off-road machine work the operating hours count instead of mileage. Less hours, less maintenance such as oil change and part replacement.
- Increasing resale value. Having fewer hours on the engine improves the value of the used machine.
- Reducing the wear of auxiliary components. Radiator, water pump, EAT, compressors… all these components may wear out faster with excess idling hours.
Also, one factor is the engine noise. Often, the engine is idling while working outside of the soundproof cabin, which exposes the operator to the noise. Slowing down the idling can also reduce the noise.
Fast and slow idling
When AGCO Power collaborates with machine manufacturers, there are two main ways to reduce idling and its negative effects. The first is having two idling speeds: slow idling when the gear is at neutral and for example the handbrake is on. When the engine must be ready to react instantly, the 200–300 RPM higher fast idle kicks in.
“Slow idling reduces noise, engine wear, emissions and fuel consumption,” Heikki Hihnala says. “Less RPM, less wear.”
Another method is to set a limit to idling time, making the engine automatically stop after excessive periods of idling.
“The set time limit is highly dependent on what the machine is used for and must be planned in collaboration with the machine manufacturer,” Heikki Hihnala points out. “The time limit can also be user-defined.”
Gathering data about engine use in different applications serves an important role in further optimizing the idling behavior.
“AGCO Power always looks for ways to maximize savings and also improve the user experience,” Heikki Hihnala says. “We also do a lot of research and simulations to find solutions for reducing unnecessary idling.
Driver decisions matter
As mentioned before, there are some old misconceptions about idling. In the past years, cold starting big diesels might have been challenging. Since then, much has changed.
“The fuels, oils and batteries of today are vastly superior” Heikki Hihnala says. “Also, the price of fuel has gone up, so long idling often does not make sense economically. The AGCO Power engine never needs more than 5 minutes of idling, even after hard work.”
In cold climates, idling was also a way to keep the machine cabin warm and windows defrosted. Today, the cabins are better insulated, and heating systems are often independent from the engine, so there is less need for that as well. According to Hihnala, the key to more optimized idling is raising the operator awareness with training.
“As the users familiarize themselves with new machinery, they know when to stop the engine,” Heikki says. “There is an optimal ‘eco zone’ which is of course dependent on the job at hand.”
The end of idling?
Today, we take idling for granted, but in the future it might be obsolete. Hihnala points out that most modern cars feature some sort of start/stop functionality, and the same can apply to off-road machinery as well.
”With the new hybrid powertrain systems, the whole concept of idling is changing,” Heikki Hihnala says. “High-capacity batteries enable more systems to work even when the engine is stopped. This is a fascinating area with many possibilities, and we are committing a lot of research to it.”
See also the previous articles of our CORE insights series:
CORE insights: How cooling system optimization improves fuel-efficiency (part 1)
CORE insights: Improve fuel-efficiency with cooling system optimization (part 2)