Oil Container Labels
The American Petroleum Institute (API) logo is a circle divided into three sections. The top half of the circle is the "API Service" section, which is used to indicate the quality of the oil. The lower half of the circle is the "Energy Conservation" section, which indicates the oil's degree of fuel efficiency. The center of the circle is the "Viscosity" section, which is used to indicate the viscosity of the oil. The oil container should have a "Starburst" label instead of the doughnut shaped symbol.
Multigrade Oils - These oils make seasonal changing unnecessary. They contain viscosity-index improvers that enable each oil to exhibit suitable flow properties at both ends of the thermometer.
They have labels like SAE 5W-30 or 10W-30 or 15W-40. Some may have labels like SAE 5W-10W-20W-30, in this case, just ignore the middle numbers and read the oil as SAE 5W-30.