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Optimizing Engines To Improve Fuel Efficiency
The engine is an often underused fuel-saving device. Optimizing the engine parameters of new trucks could improve fuel efficiency by 5 to 8%.

Technicians can set various engine parameters with a laptop or a specialized reader, often dedicated to a particular engine maker. Generic tools are available as well. Photo: Jim Park

What’s the most underutilized fuel-saving device on the truck? Strangely enough, it’s the engine itself.
There are hundreds of engine operating parameters, from road speed limiters to idle-time limiters and a lot more in between, that fleets can and should be programming themselves.
The fifth and latest Confidence Report from the North American Council for Freight Efficiency finds that most fleets don’t take advantage of anywhere near all the engine optimization that is available through programmable ECM settings.
According to the Electronic Engine Parameters report, released in February at the annual meeting of the American Trucking Associations’ Technology & Maintenance Council, multiple barriers have stymied industry adoption of such technologies. The report cites both a lack of data about the true performance gains offered by these technologies and a lack of confidence in the data that publicly exists today.
NACFE says a fleet that truly optimizes the parameters of its new trucks by tailoring them to its operations could obtain fuel efficiency improvements of 5-8% compared to leaving those trucks set to the factory default settings. By changing just a handful of key setting, savings of 3-5% are easily obtainable. In some extreme cases, fleets have reported mpg gains for certain individual trucks of as great as 20%.
Best of all, tweaking the settings to suit your operation costs nothing, it weighs nothing, requires no maintenance and only has to be done once.
“It’s pretty well money in the bank,” says Mike Roeth, executive director of NACFE.
In developing this confidence report, Roeth says NACFE first consulted with the engine manufacturers to gain a better understanding of all the customer-programmable parameters. Then the team fanned out to get the fleets’ take on which of the parameters they were aware of and which they actually set themselves.

NACFE found three tiers of acceptance among fleets: those that left the factory default settings unchanged; those that recalibrated a few key settings such as top road speed and idle time limiters, pedal/cruise power settings etc.; and fleets that dug right into the ECM to optimize their engines.
“Unfortunately, we found that OEs and dealers do not actively promote customizing the settings,” Roeth says. “The process itself can be daunting given the hundreds of settings and the way many of them are inter-related. It can take lot of effort to understand, but dealer should be able to help you through it.”
NACFE identified eight barriers to changing the settings that arise at three specific points during the optimization process, among them:
Understanding Parameters
The large number of parameters available requires extra effort to fully understand.
Interrelations between multiple parameters and/or between parameters and other systems on the truck.
Selecting and Ordering
Parameters:
Each engine OEM has its own terminology and brand names for its parameters, and even some slight differences in how they function. Even within a single OEM there will be differences from one engine model to the next.
The majority of fleets have multiple years and models of engines in active operation, sometimes from multiple OEMs.
Maintaining Parameters
Variation in service tools and lack of telematics: Changes in duty cycles or even insights from new truck performance data may indicate that a certain parameter should be altered on a group of trucks. But right now changing parameters requires someone physically connecting with the truck. This can be a time-consuming task for a large fleet. Telematics technology would allow for parameters to be updated remotely.
Negative reactions from drivers: Fleets must communicate the benefits of parameters to their drivers, as often a driver’s initial reaction to anything that places restrictions on vehicle operation is quite negative.

The full report, available on the www.truckingefficiency.org website, offers a suite of best practices to help fleets, large and small, get the most from the fuel-saving potential of their engine’s electronic controls.
These include spending time with OE reps and dealers to discuss parameter settings, building parameter templates that cover a group of similarly specified trucks, keeping detailed records of the setting changes and conducting checks to verify the setting are correct.
“It was a bit surprising to hear from fleets that believed the parameters they had access to change were mostly safety or compliance related,” says Roeth. “There are so many more ways to set up an engine so that it can deliver best performance with the least possible fuel consumption. We saw documented proof that savings of up to 8% are achievable and at really no additional cost. I hope more fleets take a serious look at what they can do on their own, or maybe with a little help from their dealers. It’s worth asking those questions.”
The full list of Confidence Reports can be found at www.truckingefficiency.org
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