This is a good question. I am sure that a few will chime in. I would ask yourself a few questions. How much do I drive my car? Is my engine sealed well?(leak oil) Can I afford the extra cost? How often do I change my oil? I personally like the extra protection that synthetics provide. The oil does not break down as easy as conventional oils do. You may see a slight mileage increase and should gain engine life also. Synthetic oils will leak from an engine that did not leak with conventional oil though! Good luck with your decision.....