Ok, this may be a long post so bear with me. This goes back to the "burns my brain with more power = better fuel miliage. Let me tell you what I have experinced and you tell me whats going on.
First of all check my signature. Now, this weekend went on a long trip to Little Rock then to Atlanta then back here. Picked up a 3200 pound load split between a small trailer and truck bed. Taken a route that put us through some really good long steep grades, time to test the box. Wish I had taken my diagnostic scanner, would have a little better info. The banks box no matter what setting your on does not make power untill 1800rpm and a given amount of throttle. I went thru several settings and all were noticably different. When I set the cruise setting 5 was the most enjoyable to drive. Some of these grades required kickdown to maintain speed at 70 but with the box on and at 70mph the program kicked in when a certain throttle position was reached and the power came on and did not kickdown. After several intentional passes on the same road I started noticing the following, Box off-cruise on, thorttle up at the start of the grade-boost pressure to 20lbs, EGT to 900 and lift pump pressure dropped from 8.5 lbs to 6., halfway up the cruise demanded enough throttle to cause kick down to maintain speed. Came back down and tried all the settings and at level 5 was the best for cruise with no more load than I had. Everything the same but at level 5 the following happended. Started out at the bottom EGT and boost went up and fuel pressure went down, at 70 it turn 1950rpm. Then when a certian throttle position was reached the engine changed its tone, EGT goes down 100 degrees, boost comes down 5lbs and lift pump pressure goes up a 1/2 pound. Even the throttle pedal was returning to a less throttle position! The truck litteraly feels like it got pushed up the grade. Is the fuel timming is what is being changed at that point? With the fuel pressure coming back I could only belive that fuel demand is being reduced. On level 6 the box will just flat out run the cruise control up the grade. After the load was delivered I just left it on 5 and it picked up approx 2 mpg, not on the trip computer but by the tank full and caculator. With the box off and at 75 mph I ran 17 mpg, on 19 mpg. No difference in milage at 59 mph which is allmost allways 24 mpg. At 59 mph it turs 1650 rpm which is too low for the Banks program to activate. When I added throttle myself on level 5 I noticed that the fuel demand went up as the pressure gauge dropped, EGT went to 900 and boost was at 25lbs and I thought I was going to pull the hitch apart! So there also must be a point that the fuel rate is added as well as the fuel timming too. Is that right or am I missing something??.