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.
Synthetic oil is used as a substitute for petroleum-refined oils when operating in extreme temperature.. Aircraft jet engines, for example, require the use of synthetic oils, whereas aircraft piston engines do not.