Description:
The Auto Retarder in Cruise Increment parameter works in conjunction with the Auto Retarder in Cruise parameter and controls the retarder level. It requires that Auto Retarder in Cruise parameter to be programmed to a value other than 0 (Zero).
Example: The cruise speed is set to 55 MPH and Auto Retarder in Cruise parameter is programmed to 3 MPH and Auto Retarder in Cruise Increment is programmed to 2 MPH. When the truck accelerates to 58 MPH, by going down hill, the Low retarder level will activate. If the truck continues to accelerate, Medium level retarding would activate at 60 MPH. High level of retarding will activate if the truck reaches 62 MPH.
Available:
All electronically controlled on-highway engines covered in this handbook
Range:
Advantages:
Auto Retarder in Cruise Increment allows the driver to customize the Auto Retarder in Cruise feature to match his/her driving style.
The Auto Retarder in Cruise feature provides drivers who are “graded” for incentive purposes, an automatic method to control the amount of time above VSL.
Disadvantages:
Programming the Auto Retarder in Cruise Increment parameter too tightly can result in a degraded fuel economy. For instance, if it is set to zero, and the Auto Retarder in Cruise parameter is set to 1 MPH, then all six cylinders will retard when the vehicle exceeds cruising speed by just 1 MPH. This can result in less desirable fuel economy.
Recommendations:
Program the Auto Retarder in Cruise Increment to 2 MPH. This will allow for all three levels of braking to be used for smoother decel on moderate grades
If High level of retarding is required, program the Auto Retarder in Cruise Increment to 0 (Zero). If this is done, Soft Cruise should not be used, since it requires 2.5 MPH to work properly.
Set the Auto Retarder in Cruise Increment parameter to the preference of the driver, bearing in mind the potentially negative affect on fuel economy if the increment is set too tightly.