[KWTrucker]

I have super singles on the tractor, can't get them for the trailer. I
don't have the budget/time to cut the axles and make drop axles, then
cut out the decking so the larger diameter tires would fit the
trailer. That is aside from the fact that doing so would cut up a
pretty new aluminum deck trailer, and limit some of the loads I could
haul. The trailer is basically a flatbed that drops down once it
leaves the tractor and the trailer uses ultra low profile tires. There
is little that can be done from a practical sense for aero mods to the
trailer and tractor/trailer interface as every load I haul is
different. If it was a box type trailer I would build some sort of gap
filler, round the upper edges, and skirt it, but this is a flat bed
type trailer. The exhaust is already routed under the cab, the sleeper
is mid-height which is too low for some loads, too high for others,
but practical on the inside. There are cab extenders on the sleeper
and I have considered extending these further. Mudflaps on the tractor
are drilled out just in case it makes a difference. They are also cut
down to the exact width of the super single tires. Homemade generator
(alternator running through inverter) provides standby power for
fridge, AC, sink, water supply, etc when parked. Up to about 85
degrees ambient I can used the electric AC (the one I installed for
night time/parking) in the sleeper to cool the cab as I drive, and
this lowers the engine intake air temp 8-15 degrees since the factory
AC condenser is mounted in front of the aftercooler. (When running
really really light, I can see the mpg drop slightly as the engine air
conditioner is engaged). Gearbox and differential oils are synthetic,
I am still using petroleum oil in the engine, which I change based on
analysis, typically every 40,000 miles. Flashing roof light for
oversize loads folds down behind the cab when not being used. Cruise
speed is 55 mph, 1100 rpm. (peak torque is 1200 rpm, general practice
is to gear 100-200 rpm above peak torque). Its a bit doggish at 1100
rpm, but not bad. 13 speed transmission splits the top gears in 200
rpm increments which makes the 1100 rpm feasible. Laptop monitors
engine ECM including intake air temp, fuel temp, atmospheric pressure,
tire pressure (Pressure Pro), etc. CB antenna is steel wire (smallest profile I can
find). Mirrors, hood, and cab are already "aero" though I have
wondered about trip wires at strategic locations. (I think DOT "requires" real mirrors, at least its not a fight I want to fight right now). Side winds seem to
be the absolute worst, and if you see pictures of the trailer, you
will probably instantly see why.

I own the truck and the trailer. I don't mind going pretty radical,
though I am pretty limited by time. Ground clearance is an issue,
especially RR tracks. I am planning to hang the side tool boxes so
they can both flex and lift as I high center them. Engine is
Caterpillar ACERT 15 Liter, 435 hp, 1650 ft-lb torque @ 1200 rpm,
compounded turbo intercooled and aftercooled. Average mpg over the
last year is 8.5 mpg. Industry average for this type of truck/freight
is 6.0 and some are getting as low as 4.5. The money I save in fuel
makes it practical for me to make a living doing this and leaves a bit
left over to experiment with, though time is really a bigger factor.
Whatever mods I made MUST be easily removed/hinged away, etc to
service the truck on a daily/weekly basis. The area I am trying to
focus on at this time is the lower parts of the truck, wheels on down.
I was pondering some sort of air dam, increased tractor skirting
possibly covering the super singles as they sit in just slightly as
compared to the duals, and then "skirting" the trailer with continuous
tool boxes.

Other mods in the long term are lift axle on the trailer, convert the
tractor to single drive with liftable idler. Also working on some sort
of retractable tarp for the upper deck/front part of the trailer that
would act as a gap filler for many of my loads. Also have considered
cutting up the hood to vent the air through the top, removing factory
AC and adding electric on the cab roof, and filling in the step areas.

Bottom line, it makes money now, and needs to continue to do so in the future.

How do I post pictures? thanks for the reply

Myron