My customers always think that when the price of crude oil drops, the base oil price will drop too base oil comes from crude oil too. In fact all oils including of petrol and kerosene comes from crude oil.
But that is not the case with Base Oil. Base Oil price is subjected to the demand and supply of it rather than the Crude Oil price. Recently a few Base Oil manufacturing plant closed down. Even though the Crude Oil price drops, the price of Base Oil kept on escalating. That is why your car lubricant is so expensive now.