Synthetic lubricants are usually manufactured using chemically modified petroleum components rather than whole crude oil, but they can also be synthesized from other raw materials. Synthetic oil is used as a substitute for lubricant refined from petroleum when operating in extreme temperatures because, generally speaking, it provides superior mechanical and chemical properties to those found in traditional mineral oils.
Part-synthetic (also called synthetic blend or semi-synthetic oils) are blends of conventional mineral oil and synthetic oil.
Synthetic-blend oils offer the best of both worlds. They provide better overall performance than conventional oils at a lower price than fully synthetic oils.
Advantages of synthetic oils
There are five main advantages synthetic oils have over conventional oils:
- Superior temperature resistance – Synthetic oils can safely handle higher operating temperatures without breaking down. Synthetic oils are thus recommended for hot climates as well as heavy-duty, turbocharged or hard-use applications.
- Better low-temperature performance – With easier engine starts in cold weather, synthetic oils are ideal for cold climates. Synthetics flow freely at extremely low temperatures (-30 to -40 degrees Celsius) unlike synthetic oil, which tends to thicken in cold weather.
- Better engine protection – High-speed engine parts can shear additives as motor oil travels through the engine, thinning the oil. Full synthetic motor oils resist shear under heavy loads better than conventional oils. This helps synthetic motor oil maintain its viscosity grade, enabling it to withstand more extreme engine conditions and offering better engine protection.
- Lower oil consumption – Synthetic oils experience less “boil-off” than conventional motor oils. A good synthetic will lose only about 4% of its weight when run at 400 degrees for six hours, compared to a 30% loss for conventional petroleum-based oil. The lower evaporation rate translates to less oil consumption and higher oil-drain intervals of up to 30,000km.
- Cleaner engines – Synthetics don't break down or sludge up as fast as ordinary mineral-based oils. This maintains lubrication efficiency during short city trips in winter.