Why do we refine oil

Is it because it burns better and longer if it's refined? When older civilizations burned unrefined oil did it burn less efficiently? What are the main differences (for purposes of burning) between refined oil of today and unrefined oil of the past?

Crude oil is a mix of numerous hydrocarbons and the actual composition depends on where it's from. https://en.wikipedia.org/wiki/Benchmark_…

Refining separates the oil into its components where they can be put into different products depending on their properties. This allows us to make devices that are optimized for a specific type of oil product. Refining also removes any impurities and breaks some of the less-useful heavy molecules into lighter ones

"Refining" something is the same as "purifying" (purifing?) it. Unrefined oil does not burn as controlled and efficiently as refined oil. When we refine oil we take out anything that doesnt really belong such as water or other gasses and liquids that may have mixed with eachother in the ground before being pumped into a tank. If those gasses and liquids were still in our oil then the way the oil reacts in our cars and planes and houses would be very random and uncontrolled.

oil a very usefull and valuable product all throughout its life, not very useful unrefined but there are many levels of refinement. oil is used to make plastic. the casing of your phone and the casing around all the wires within it are oil. the petrol or diesel in your car is oil. the food packaging in your fridge is oil. there are many levels of refinement of oil and at every level is another use for oil. that is what makes oil very, very expensive and resourceful. not just its use as gasoline. substitute the word 'plastic' for oil and you have an idea of how valuable oil is.

http://spease.hubpages.com/hub/barrelofo…