There are four sorts of crude oil products. Light unrefined petroleum has a low thickness, and is in this way less demanding to transport and refine. Artificially, it is “closer” to completed items, such as, oil and diesel, and accordingly requires less refining and preparing. This makes it more profitable and in this manner more costly to buy. Overwhelming unrefined petroleum, by complexity, has a higher thickness, and is harder to transport and refine. This makes it less expensive to buy.