The 5w30 is engine oil which used mainly in diesel engines and patrol. In today’s time, 5w30 is multi-graded oil that has the range from higher viscosity grade of 30 to lower viscosity 5. Its working viscosity is from 9.3 to 12.5mm2/s. The 5w40 is also engine oil that indicates the weight or viscosity of… Continue reading What is the Difference Between 5w30 and 5w40?