Viscosity tells you the speed at which the oil will flow. The lower the viscosity the faster the oil will flow at 210 degrees fahrenheit as in an SAE30 weight oil. Any oil with a W attached such as SAE 10w30 means the oil was tested at a cold temperature and will flow as a 10 weight when it is cold and then performs as a 30 weight at 210 degrees.
5W-30 is the preferred oil viscosity
The 5 and 30 refer to the relative viscosity of the oil when it is cold (5W) and when it is hot (30W). A 5W-30 oil behaves like a 5W thin viscosity oil when the engine is cold, and it behaves like a 30W thicker viscosity oil when the engine is hot. A very thin viscosity is undesirable in a hot engine. In very high temperature situations, an even higher viscosity range, up to 50W, might be called for. Always go by the engine manufacturers recommendations.
The wrong viscosity of oil in your engine.
5W30
30w
The viscosity of the oil may not be heavy enough to protect the engine.
As the engine wears, the bearing clearances become a little larger, REQUIRING that you use a higher viscosity oil to maintain oil pressure. If using the recommended oil viscosity results in low oil pressure, you should certainly switch to the 10W40. HOWEVER, if the engine can maintain oil pressure using the recommended oil viscosity, you will get better economy and the engine will perform better.
Of course you can but when you do you are changing the viscosity of the oil. Your engine requires a certain weight or viscosity of oil. Use only the weight oil recommended by the manufacture.
Using a high-quality synthetic engine oil with a low viscosity can help reduce friction in a car engine by providing better lubrication between moving parts. It is important to follow the manufacturer's recommendations for oil viscosity and change intervals to optimize engine performance and reduce wear.
Well Engine oil manufacturers keep the manufacturing techniques secrets with each others. Most motor oils are made from a heavier, thicker petroleum hydrocarbon base stock derived from crude oil, with additives to improve certain properties. The bulk of a typical motor oil consists of hydrocarbons with between 18 and 34 carbon atoms per molecule. One of the most important properties of motor oil in maintaining a lubricating film between moving parts is its viscosity. The viscosity of a liquid can be thought of as its "thickness" or a measure of its resistance to flow. The viscosity must be high enough to maintain a lubricating film, but low enough that the oil can flow around the engine parts under all conditions. The viscosity index is a measure of how much the oil's viscosity changes as temperature changes. A higher viscosity index indicates the viscosity changes less with temperature than a lower viscosity index.
Well Engine oil manufacturers keep the manufacturing techniques secrets with each others. Most motor oils are made from a heavier, thicker petroleum hydrocarbon base stock derived from crude oil, with additives to improve certain properties. The bulk of a typical motor oil consists of hydrocarbons with between 18 and 34 carbon atoms per molecule. One of the most important properties of motor oil in maintaining a lubricating film between moving parts is its viscosity. The viscosity of a liquid can be thought of as its "thickness" or a measure of its resistance to flow. The viscosity must be high enough to maintain a lubricating film, but low enough that the oil can flow around the engine parts under all conditions. The viscosity index is a measure of how much the oil's viscosity changes as temperature changes. A higher viscosity index indicates the viscosity changes less with temperature than a lower viscosity index.
viscosity