Part is undoubtedly better fuel mileage but the major reason oil prices are under assault and will be for some time is because of frakking. The US discovery of frakking and removing natural gas and oil from what were considered impossible sources has given the US economy an incredible boost over the last 12 years.
The US now produces a tremendous amount of natural gas that is becoming the way we produce power in the US and being used for more and more things. While it can’t be used to drive cars ( there are some but it is a marginal and somewhat dangerous way to power a car ) the main effect is to reduce our need for oil in power production.
Natural gas prices have fallen from fracking to a small fraction of the price of oil. The result has been a dramatic drop in our need to import oil from our enemies. An awesomely good thing on multiple levels.
One of the most dangerous aspects of the stupidity of democrats was that they wanted to stop frakking. Doing so would erase trillions from the US economy, have cost millions more jobs and made us more dependent on foreign sources of energy.
A major strategy of the Trump admin is to build ALL US energy industries. Coal, oil, natural gas, solar, whatever. Let the market decide but unleash the regulations where democrats were trying to perform industrial policy and pick the winners let the market decide. The subsequent boost in US energy supplies will eventually turn the US into an energy surplus and generate millions of new middle class jobs as well as completely eliminate our demand for foreign oil and energy. In fact we will be making billions from selling energy.
The extra real jobs will produce more jobs and tax revenues as well as dramatically increasing the wealth of America and our economic situation and weaken our opponents.
The Arabs know the game is up. With frakking the US and the world has a way around dependence on the Middle East. Saudi’s and other Arabs are beginning to realize that their oil monopoly is ending and they cannot depend on this is their only source of income. I believe this is a major reason why they have become more flexible on peace in israel and willing to work with Trump.
The US is in a good position to strengthen its hand in many ways around the world because of sane policies of Donald Trump that were not going to be the case under democrats.