Synthetic oil has a number of advantages over conventional mineral oil. Though the cost of synthetic oil is higher, car owners should consider whether the advantages are worth the extra cost for their cars.
On average, synthetic oil costs almost twice as much as conventional mineral oil. Considering that synthetic oil does not require being changed as often as conventional mineral oil, the cost is not as high as it seems at first. Synthetic oil is still a little bit more expensive in the long run, however.
Synthetic oil is more resistant to viscosity breakdown, which is why it can be used longer than conventional motor oil. The loss of viscosity causes motor oil to protect engines less well, as oil whose viscosity has broken down flows more quickly away from where it is needed.
Engine Oil Contaminants
Engine oil contaminants are one of the primary reasons that oil changes are necessary to keep your car's engine in good shape. Unburned fuel, carbon, metal particles, and other abrasive matter collect in the oil and can cause engine wear. Oil filters help to trap these particles, but some remain in the oil. This is one area where synthetic oil has no advantage over mineral oil.