Best Answer: People have always argued what the best oil out there is. And most people either go for royal purple, castrol, and mobil 1. I personally choose Mobil 1, but the choice is really opinion based.
The sores may occur singly or in groups and vary from about 1/8 inch to 1 -1/4 inch in diameter. The sore may be painful for three or four days, but complete healing usually takes ten to fifteen days. Canker sores may recur many times each year. Causes: No one knows what causes canker sores. They may be caused by a virus, may be a form of allergic reaction or may result from an auto-immune condition (meaning that the body has developed an immune reaction against its own tissue).
What causes canker sores? No one knows what causes canker sores. The vast majority of people who develop canker sores do not have another problem as the cause. Both hereditary and environmental causes of the disease have been suggested, but the exact cause is not clear. A number of factors have been suggested to precipitate outbreaks in susceptible individuals.