The different oil specifications for vehicles cater to different driving conditions. Oil specifications include synthetic, high-mileage and conventional motor oil. The Society of Automotive Engineers developed the rating system used for motor oils.
Synthetic motor oil provides a high level of engine protection and lubrication. The oil is made of blended, precisely controlled ingredients to achieve better cleansing qualities, better protection at startup, and better protection against heat buildup.
Synthetic blend motor oil is a variation of synthetic oil which combines conventional and synthetic oil to provide additional resistance to oxidation. The oil is best for vehicles that regularly carry heavy loads or frequently operate at high RPMs, such as vans, trucks and SUVs.
High-mileage motor oil is specifically designed for vehicles with higher mileage or older vehicles. The oil has unique viscosity and additives designed to help restore engine compression, improve combustion and seal oil leaks.
Conventional motor oil uses base oils and is designed to meet car manufacturers' criteria for viscosity, breakdown resistance and heat tolerance. Types of conventional oils vary from high-quality to adequate lubricants. This type of oil is best for late-model cars whose owners have routine driving habits; it is also ideal for low-mileage cars.