The lowered position is for long distance haulage of the trailer in {HEAD ~ order} to achieve {TAIL ~ fuel economy} 
to achieve
The lowered position is for long distance haulage of the trailer in { HEAD ~ order } to achieve { TAIL ~ fuel economy }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL