Pulled the 20' enclosed trailer from Raleigh to just west of Rock Hill, SC this past weekend. First pull with the 5 Star 93 octane tune. A little better than the 87 but nothing to get excited about. No better fuel economy either. Still much better than stock, though.
But here's something that has happened several times, whether I'm running stock, 87 octane tune, or the 93 tune this past weekend. When we left home Saturday afternoon, the truck just felt like it was "tired". Transmission often downshifted just to climb the slightest of inclines. Another way to describe it would be what it would feel like if the trailer had a parachute behind it. Interstate travel virtually the whole way and speeds between 65-68 mph. Truck showed 7.8 mpg.
Truck sat the entire time once arrived until we left for home Sunday afternoon (24 hours). When we left, the engine had new life. It pulled the trailer as if it weighed half of what it does. Transmission hardly ever downshifted because the torque felt almost "diesel-like". At one time, mpg's were at 8.9 and finally averaged 8.7 once we stopped for a drink about two hours after we left. When I cranked the truck back up from the 15 minute break and got back on the interstate, it was virtually back to its former self. The parachute was back out and I reset the mpg meter and we were back to the 7.8 mpg range. It drove like this pretty much all the way home.
The truck did fine, either way. But its amazing how different it seemed to perform. I wondered if the computer had adjusted things because of the long tow but if that's the case, why did it go back to its former ways once we stopped for just a 15 minute stop.
I don't think this is all in my head. It certainly feels different and the mpg's tell the story. I don't think this is a 5-Star thing either because its done it in stock form as well.
If there are different modes to this motor when towing or not, how can I keep it in that mode it was in coming home for those two hours? It was amazing for a gas engine.
Yes the 6.2 does feel like it has split personality, after pulling with a V10 for 13 years and now with a 6.2 the 6.2 will adjust to the load faster than the V10 did. I find that if I'm cruising down the road pulling the trailer on flat roads it feels like it has adjusted itself back a bit but if you get on it the power comes back in short order.
When ever I state any kind of mpg that I am getting I try to make it over a long pull and if I can in both directions to compensate any road and wind conditions. With my Lariat and the way you can track your mpg with the A, B and instant setting you can track both directions individually and play with the instant setting to see how different speeds and and the way
you driving at the time affect the mileage.