4 Aug 2019 The SAE Viscosity Number or "Grade" according to the initial SAE J300 This means that two different oils that appeared to have an identical 17 Nov 2016 Read on to learn more about the different oil grades and specifications, and what they mean. Engine problems? Call us on 0800 88 77 66 for 14 Aug 2017 Legally, the term “synthetic” has a pretty loose definition. The majority of motor oils can be divided up into five different groups. An oil's group The petroleum base oil alone may have the properties of an SAE 5 grade oil.