On top of this, good oil prevents dirt build-up and deposits by keeping them in suspension. Motor oil even protects against sludge and fights oxidation, keeping the oil fresh and minimising acids which can cause corrosion. In short, oil matters.
What is oil viscosity?
Viscosity is an important criterion of any lubricating oil. It is a measure of a fluid’s thickness or resistance to flow. For example, honey is thick and water is thin, so honey has a higher viscosity than water. Oil viscosity needs to suit the right ambient temperatures. If it’s too thick when the engine is cold, it won’t move around the engine. And if it becomes too thin when the engine is hot, it won’t give the right protection to the engine parts.
Optimising an oil’s viscosity, or thickness, helps maximise energy efficiency while avoiding component wear. Viscosity modifiers increase the viscosity of your oil at high temperature but have little effect on low-temperature viscosity. These enable your oil to flow properly when cold and also to remain thick enough to protect your engine components at high temperatures.
Lower-viscosity grades of oil such as Shell Helix Ultra, make it easier for your engine to start from cold because they present less resistance to moving parts and hence take less power from your engine. This also means that you get enhanced fuel economy.
To find the right oil viscosity for your engine, check your manufacturer’s guidelines and bear in mind the weather conditions you live and drive in. For our recommendation, try our simple Shell LubeMatch tool.