The Grade of oil you use depends on Mfg specifications, and personal preference. I personally use "Castrol" grade 20/50 because it is a quality oil, and multi-viscosity. Meaning that when it is cold it is this, and as it heats up in get thicker. If you are asking what SAE Grade oil is, it is the Society of Automotive Engineers grading oil by viscosity, or the size of the globules of the oil. the smaller the number the thinner the oil 5 is thinner than 10 etc. Mutiviscosity is a combination such as 10/30 or 20/50.
Sae-20w
sae document j300 defines the highest single grade as 60. this is in reference to viscosity and not the quality of the oil
SAE 10w30
SAE 5w40 full synthetic oil.
SAE 10w30 synthetic.
the oil grade in which is specified by the parts manufacturer
SAE 5w30 weight oil is required.
sae 30 summer5w30 winter
SAE 30
SAE 5W30 or 10W30 I would recommend the SAE 5w30 synthetic blend.
SAE 5W-30 is the preferred.
SAE is an acronym for the "Society of Automotive Engineers" and when used in conjunction with tool grade or measurement (not oil), is a standardized unit of non-metric measurement. Simply put, in measurements it means "Non-Metric". The name "SAE" used to grade motor oil has a totally different meaning, although instituted by the same society.