It is genetic - in my family there is no history of it as it is a recessive gene but my mum and dad were both carriers. In Scotland up to 13% of the population has red hair, but around 40% of the population is thought to carry the recessive gene responsible for the world's rarest natural hair colour.
On the other hand, synthetic base oil molecules are chemically controlled, which provides increased ï¬ lm strength and lubricity over petroleum oils. The performance qualities of base oils have a marked impact on the performance qualities of the ï¬ nished product.
For synthetic liquid hydrocarbons, see Synthetic fuel. Synthetic oil is a lubricant consisting of chemical compounds that are artificially made. Synthetic lubricants can be manufactured using chemically modified petroleum components rather than whole crude oil, but can also be synthesized from other raw materials.