Two more quick additions, that may or may not apply to the OP.
1) The gear that the trans will shift to when engaging the Jake Compression or Exhaust Brake assist, may vary. (I saw 2nd gear was mentioned in one post. In contrast, our 2004 Country Coach with the 30XX series trans - down shifts to 4th gear.) This is also something that can be changed, along with a few other setting related to how things behave with cruise control.)
2) I LOL at myself, after about 18 months of driving our coach, when I learned that on our rig (as it was programmed), that in order to down shift below 4th gear while in Jake Brake mode - you had to hit the down arrow button multiple times. (The trans still feel it is in 6th gear (or whatever gear you were in before activating the Jake). So to get down to 3rd gear, you need to tap the down arrow three times (5th, 4th and land in 3rd). And if on a real steep hill, one more down arrow will get you into 2nd:)!
For a short term usage, just get in and drive. If this is a rig you will own for along time, or put many, many thousand miles on - then do learn to read the road ahead, and use down shifts to keep the RPM's in the best power range for hill climbing. (CAT or Cummins can tell you the best RPM range for peak power, with a simple call.)
And after reading Wolfe's article back when he wrote it, and from other posts, we default drive in Economy - and manually intervene when we feel it is needed.
Best to all,
Smitty
