I run a 95 diesel dually 2 W/D with a 6 speed stick
and with my 43' trailer I get 18 mpg once I hit the
Expressway... city traffic and lights kills my mileage...
my trailer has a real small front to it(custom) so I'm
not dragging a wall behind me... also I try to keep my
revs at 2000 to 2200 which is 65 mph or a bit higher...
it has the 4.10 gear but I did put the tallest tire
on it that would fit