Ihaffcomp"lied"

I've been pumping oil and water into combustion engines, to power refineries for a while now. I've been transporting it to a very large dig site. The process as you may know is very time consuming. I've been doing it this way for a while now. So... ~Actual Question~ Is there any way to differentiate the difference between use of fuel or oil? Does it make the engines run faster? Does it supply more? Does it make any difference whatsoever? I would much appreciate any help given to me about this situation.