Your thoughts on MPG spread

You cant go wrong with a detroit, every shop can fix them.

 

I might consider buying one myself if I could get that much mpg. I think Kenworth is planning on ceasing production of the W900.

 

I know a company running hoods with tuned CATS and they're running 7-7.5 pulling flats and curtain side trailers.

 

My 99 379 with a cat has a lifetime average(since I owned it ) of 6.37. Driving right at 60. Just had an inframe don in August. Now have a 30 day average of 7.10. 60 day average is 6.89 and a 90 day average of 6.76. I keep track on fuel gauges under my same user name . I have logged every fuel up since I joined in Jan 2012. Couldn't believe an overhaul made that much difference and it isn't even broken in good yet.
Truck has 390 rears, 24.5 tall rubber. (General dd660) and a ten speed. I pull a flat and always close to 80 k and mostly oversized. By everything you hear I should have to buy $1000 s in gizmos to get this kind of mpg's.
I think buy what you like, spec it right and drive it like you have some since and it will do good. If I romp on mine I cane make it get low 4s. That gets expensive.

 

Slowing down 5mph like you said and pre emission if engine is healthy I'd say you would get the same as you currently get with a Emmision motor with the option to do better by speccing it for 60 in direct.. Personally I don't believe a full mpg aero to classic at slower speeds like 60 I know too many guys running 58to 62 that are hitting 7 plus all summer long as long as idling is kept down pulling heavy with tuned engines. drive what makes you happy kr used to rave on coranado which isn't far off from a w9