Oh, the question was asked what would ERS do? It will unlook the convertor, I believe, for starts, a few more hundred rpm to put it in a better range. If you want it to pull that low, at those speeds with that wind, there is a 6.7 out there that will handle it with ease, you pay the boo-koo dolars. Someday tho they will make an engine with as much stroke as bore, (or more) works for toyota and fords 5.4, not big numbers there, but in a lower rpm cause the stroke

 

I pulled a 5000lbs trailer all summer last year, and I must admit I never had issues getting to where I was going. All I was hoping for was a gas station at the next exit.
I averaged less that 400KMs per tankl full (32 gallon tank). Ouch.
Shifting all the time, but beacause I was going through Vermont and Maine, lots of mountains.