Vehicle owners typically know their car demands a particular viscosity and grade of engine oil according to their owner's manual but more often than not do not understand what these numbers mean.
The simple fact is that not many consumers understand the current multi-viscosity engine oil evaluations or the character of how these contemporary motor oils operate as relates to the viscosity of the oil. You can choose the best motor oil via https://lambertoil.ca/our-products/other-products/
All multi-viscosity oils may have two sets of numbers. The best (larger) number suggests that the oil's viscosity.
The most common dimension of oil viscosity is known as kinematic viscosity, which measures how quickly the oil will flow through a glass tube warmed to 100 degrees centigrade (212F) when extracted by gravity.
First, they are both 30 weight motor oils and there is no difference at all when either is in an engine at operating temperature. So both a 5W/30 and a 10W/30 have the same resistance to flow, the viscosity of the oil when the engine is running and warmed up to operating temperature.
At cold temperatures though, the use of additives and or polymer technology allow the motor oil to flow more readily, i.e. a 5W/30 motor oil will flow more easily at low temperatures than a 10W/30 and a 0W/30 will flow better still at low temperatures making them more suited to winter use than the 10W/30
This is why the old practice of changing straight grade oils to a heavier viscosity in the summer and a lighter viscosity in the winter is no longer necessary.