Ordinarily, {TAIL ~ mineral lubricating oils} are used by reason of their availability, general excellence, and {HEAD ~ low cost} 
Ordinarily , { TAIL ~ mineral lubricating oils } are used by reason of their availability , general excellence , and { HEAD ~ low cost }
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD