Vehicle Controls & Driver Behavior
The introduction of electronic engine controls in the mid-1980s included controls for idling behaviors. Over time, the number of parameters has grown significantly. The number will continue to increase as we move into the future, and ongoing developments in truck design and operation impact how fleets optimize their engine parameters.
Many diesel engines today offer customizable idle settings that can be programmed using OEM software tools. These tools allow fleets to tailor idle behaviors — including idle shutdown timers, low/high idle RPM settings, ambient temperature overrides, and PTO-related parameters — to match specific duty cycles and driver needs.
Most engines now have idle control parameters, which limit when idling can occur based on outside ambient air temperature. Many idle laws are written with the understanding that idling without interruption is acceptable for running air conditioning when the ambient air is above a specific warm temperature, and likewise acceptable for heating when the outside temperature drops below a certain point.
In addition,drivers need proper training on idle-reduction systems to ensure their effectiveness. Many fleets offer continuing education through driver meetings, newsletters, emails, or videos that can be accessed through an onboard satellite system. Since some systems are more complex than others, certain ones require drivers to conduct minor maintenance checks while on the road periodically.
Many fleets now tie idle-reduction goals directly into driver-performance metrics, allocating as much as 30% of a driver’s score to minimizing engine-off time. In one case, a carrier that weighted 30% of its driver score on idle reduction paired the program with a rapid roll-out of eAPUs, cutting average idle time by double digits and saving more than $2 million in fuel costs in the first year alone. Meanwhile, gamified platforms surface real-time excess-idling data — drivers compete on leaderboards and earn gift cards or branded swag for top rankings — driving voluntary behavior change and idle-time reductions of up to 12% across participating fleets.
Regardless of the system, drivers can help optimize the system’s capabilities by following some general rules. These measures can keep engine temperatures comfortable, extend component life, and trim 2% to 4% of total fuel spend, worth thousands of dollars per tractor annually.
Benefits
No Cost
Electronic parameters are now standard equipment, so no cost is associated with using them to control idling. However, failing to use them could lead to a lost opportunity cost.
Can Be Adjusted Around Other Technologies
Fleets can improve by adjusting temperature parameters to match their idle-reduction technologies. For instance, fleets that use trucks with fuel-operated air heaters may set lower cold temperature limits for main engine idling, as the heater keeps drivers warm in most outdoor temperatures.
Challenges
Security Concerns
Unauthorized parameter changes can compromise vehicle settings and, in some cases, lock out management access, requiring complete ECM reprogramming or module replacement. Even with password protections, technicians should not adjust settings without management approval.
Interrelations Between Parameters
Altering one parameter often requires adjusting other parameters. All parameters must be customized to the overall truck specification.
Diversity of Terminology
Each engine manufacturer uses its own vocabulary and brand names for programmable parameters, and the functions themselves may vary between OEMs or even across engine models from the same OEM.
Driver Acceptance
It can be difficult to gain buy-in from drivers who may feel the fleet is trying to restrict their driving style.
