Synthetic oil manufacturers.
Ashland oil It is Amalie
i think it is amalie oil
Caterpillar
purolator
Probably Wix.
oil
Different oil companies at different times and different regions of the country.
The gulf coastal plains, also known as the oil coast.
You don't. Add not additives to your oil. If additives worked the manufactures would add them to the oil and recommend you also do so.
Advance motor oil is made by Coastal
Depends on where you purchase the oil. Most of their oil is manufactured by Chevron. But in some areas it may be made by some other oil company.