Consumer expert Amy Davis shopped around to show you where to get the lowest priced oil change in our area. The technician may ask you if you want conventional oil, a synthetic blend (which is a mixture of conventional and synthetic oil) or straight-up pure synthetic. Synthetic Blend - This oil is a mixture of conventional and synthetic oils. This oil is not as cheap as conventional oil, but not as expensive as full synthetic oil. The compounds in this oil don’t break down as quickly as those in conventional oil, allowing you to change your oil less frequently.