[RodeWorthy]

First let me apologize to the orginal poster. I really try to make sure I don't hijack posts by getting off-topic in a particular post but I blew it during the discussion of the tow-haul mode. Seems it got off track early and I missed that. Sorry.

But since we are into it and I have had comments on my post I hope you won't mind if I wrap this up.

Thanks to those who commented on the information I provided regarding the use of Tow-Haul mode for the Duramax/Allison.

Terry,
Any information I post is considered public domain. Use it as you deem appropriate. No need to provide source information. Many times the information is my own opinion which may be right or wrong but in this instance I paraphrased the information regarding the shift points and TCC directly from an Allison publication to make sure I got it right. The info pertaining to when to use Tow-Haul mode is strictly from my own experience but I believe it to be correct.

I tried to find info directly from Ford on their application of Tow-Haul mode but could only find 3rd-party info. However, it does confirm that the shift points change between the two modes and the TCC does deploy earlier when in Tow-Haul mode.

Ford's Towing Guide for 2010 explicitly states that Tow-Haul mode can be used when operating on hills to avoid shift hunting, aid in engine-braking and to help keep temperatures under control. It does not imply that Tow-Haul must be used whenever towing. From this I would suggest it is not a requirement to use the Tow-Haul mode whenever towing and further Tow-Haul can be used when not towing.

Huck has it right -- no need to be running at 2000 RPM when a lower RPM can be achieved for the same MPH.

Hope this helps.