I, also have been using archoil over the past couple years. Recently i had a transmission replaced at a guy place in Ohio that is a big 7.3 fan and has a lot of parts for them.. He was doing the sway of the old, but in good shape, 4R100 with a new sam wyse stage 1 unit. He did take the truck out for a test drive and comment how quickly it started up and how smooth it sounded and ran on his test drive.
also we are currently pulling a 30 ft airstream, 8200 lbs, from nc up through NH and now out to washington state..
my thus far overall mileage, hand calc numbers, on my last fillup was 16.7 MPG.. now this is a combo of pulling and non pulling numbers.. I try not take the rv in such place as the route from Red Lodge montana, aka Bear tooth hwy an the Chief Joseph, (dead indian) highway routes.. we did that non pulling..
I would guess the pulling amount is 40% and 60% non pulling miles..
I did do some just pulling number and they average 12.5 to 13.6 depending on wind and we have gotten a LOT of tail or wind from teh rear quarter more than a true head or front qtr wind out west across SD, WY and WA.
I know it runs smooth, pull good,, and starts quick. Happy camper..
(ps yes that is a solar panel on bed shell,, 335 watt 24 v to help with 460 watts on AS.. ))