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.
Originally Posted by bigmac8675. Synthetic oil can last longer than regular motor oil.... at the most twice as long. (6000 miles compared to 3000 miles) Although if you baby your car or have a high performance car you should still change it between 3000-3500 miles even if it is synthetic.