Of all this crude oil, only about 35 percent of what we use comes from the states, the rest is imported from other oil producing countries, including Africa and The Middle East.
Here is a shorten version of the refining process. Crude oil is heated and the components of it are then separated,which is made possible because they each condense (form a gas) at different levels of heat. The different substances can then be mixed with chemicals or altered with heat and pressure to change the basic structure of the substances and change them into different kinds of fuels.
The crude oil is brought to a refinery, where it becomes gasoline. and other products. The gas is then transported through a pipeline or an oil tanker to its destination where it is put into oil trucks to be delivered to gas stations. Once there it is pumped into underground tanks which connect to the pumps for fueling vehicles.
An oil tanker is a ship that can carry up to 1.26 million barrels of gas, and the oil trucks can hold 9,000 to 10,000 gallons of gasoline.
How is the grade of gas determined? The grading is based on the amount of octane in the gasoline, and a gas station can sell one or more grades. Each vehicle owners manual will tell you what the octane rating should be for the fuel you put in your car. You should find out what grade your car needs and use that grade for your vehicle to run at its best.
Different states have different requirements for gasoline, in regard to the emissions ratings they must meet, so sometimes other ingredients are mixed with gasoline. Sometimes this is done with ethanol which burns cleaner than gasoline.
This is done to help the polution levels that have been found to harm the environment and cause health problems Do you know what your states emission regulations or how they are trying to improve the conditions in which you live?