Slow reacting cruise control

All of ours do that too. I make sure to let off a hair before the hill, and then wind up that turbo at the base.

 

On a 3406 motor you can set the cruise to hard or soft. Soft is better for fuel mileage. They can also adjust how much the vehicle speed drops before applying fuel or engine brake to slow down if you are gaining speed. I would the smaller engine has the same parameters in the ecm Any dealer can get the info from ecm.

 

I had the cruise on my c-12 changed from soft to hard settings,,,made a huge difference,,,im sure it sucks back more fuel,,,but definetly helps keeping up with the flow of traffic!!!

 

Ditto. A person can set the cruise for hard or soft in the ECM settings. For Varithms, forget dealerships when it comes to doing anything serious with the engine unless it was a proprietary engine made by the truck manufacturer. If it is a Cat, Cummins, or Detroit, more often than not you will get better results taking it to that brand shop. It never ceases to amaze me how a truck dealership will hang engine logos on the side of their building, but don't even know how to set various parameters in the ECM.

 

Came across something the other day, since we are talking about ECM settings. A O/O that regularly runs Canada, where they want all trucks limited to 65, and will sometimes plug up a truck to check. This guy had the limiter set to 65, but also has the driver reward feature set so thst as long as the truck gets above 3 mpg (and he is always above that), the ECM rewards him by allowing him to go over 65. I think he said he could go up to 80. If Canada checks his ECM speed limiter, which they have, it shows the truck limited to 65.

If the US gets around to doing that speed limiter game like the ATA wants, I have got to remember that one. As a side note, I may do this type of thing in the near future anyway. Imagine an Indiana bear stopping you for going over 65. You take it to courf with a current ECM printout showing the truck limited to 65. "Oh well, officer, your radar gun must need recalibration".

 

First off Cats are notoriously slow to react, ever drove an Auto shift with a Cat, then try a Detroit. If you take it to a truck dealer they do the whole thing not just yellow part, setting parameters is not rocket science, and may companies have a fleet setting for all there units, and passwords to stop drivers from playing with the settings. Many companies ask for a complete print out when ever the truck is brought in for a repair. Many times we would get a response back that they wanted certain things changed, and sometimes the driver that brought it in did not pick it up.
If you are driving and you know the truck is going to slow down you could use the pedal to the right. When you tap the cruise increase button in a Cat it takes a while to do anything do it in a Detroit and it is instantaneous. Any of you that drive a Cat auto shift you have my sympathies. When I took one for a road test I would only go on certain routes 7 seconds between shifts and hitting every gear is scary slow if you are trying to merge in traffic.