Pennzoil recommends using conventional motor oil for low-mileage cars. Some newer engines require synthetic oil, so car buyers are advised to check the owner's manual of a vehicle before adding oil to avoid potential engine problems or a voided warranty.
Conventional motor oil uses base oil that is augmented with chemical additives to meet the levels of heat tolerance, breakdown resistance and viscosity specified by engine manufacturers. Conventional oils are available in different ranges of viscosity and quality levels and are appropriate for late-model, low-mileage cars used for routine local driving and vacation driving at moderate speeds.
Synthetic motor oil uses a specially designed blend of man-made ingredients to produce a lubricant with higher levels of engine protection than conventional oils.