5W-20, 10W-30, and 20W-20 are common weights of what commodity?
Motor oil a W designation. The 11 viscosity grades are 0W, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, and 60. These numbers are often referred to as the "weight" of a motor oil, and single-grade motor oils are often called "straight-weight" oils. For single winter grade oils, the dynamic viscosity is measured at different cold temperatures, specified in J300 depending on the viscosity grade, in units of mPa·s, or the equivalent older non-SI units, centipoise (abbreviated cP), using two different test methods. They are the cold-cranking simulator (ASTM D5293) and the mini-rotary viscometer (ASTM D4684). Based on the coldest temperature
Motor oil SAE 30 at 100°C. Therefore, there is one set which measures cold temperature performance (0W, 5W, 10W, 15W and 20W). The second set of measurements is for high temperature performance (8, 12, 16, 20, 30, 40, 50). The document SAE J300 defines the viscometrics related to these grades. Kinematic viscosity is graded by measuring the time it takes for a standard amount of oil to flow through a standard orifice at standard temperatures. The longer it takes, the higher the viscosity and thus the higher the SAE code. Larger numbers are thicker. The SAE has a separate viscosity rating system