How much do you know about the oil you put into your customers’ car? Did you know that there haven’t been any really significant changes in base oil refining processes for the last 50-70 years? All that changed when Pennzoil pioneered a new base oil refining process called hydrocracked technology. Base oils are the primary lubricant in motor oil, and represent 80-90 percent of the total package after oil additives have been mixed in.