Viscosity
The main difference between 10W-40 and 5W-30 motor oil is their viscosity. Viscosity is a measure of how thick or thin a fluid is. The higher the viscosity of an oil, the thicker it is, and the lower the viscosity the thinner it is.
The "W" in 10W-40 and 5W-30 stands for "winter." The number before the "W" indicates the oil's viscosity at 0 degrees Fahrenheit (-18 degrees Celsius). The lower the number, the thinner the oil will be at low temperatures.
The number after the "W" indicates the oil's viscosity at 100 degrees Celsius (212 degrees Fahrenheit). The higher the number, the thicker the oil will be at high temperatures.
So, 10W-40 oil is thicker than 5W-30 oil at all temperatures. This means that 10W-40 oil will provide better protection for your engine from wear and tear in high-temperature climates, while 5W-30 oil will provide better fuel economy and performance in low-temperature climates.
Additives
10W-40 and 5W-30 motor oils also differ in their additives. Additives are chemical compounds that are added to motor oil to improve its performance.
Common additives include:
* Detergents to keep the engine clean
* Dispersants to prevent dirt and sludge from forming
* Anti-wear additives to protect engine parts from wear and tear
* Antioxidants to help the oil resist oxidation (breakdown)
The type and amount of additives used in a motor oil can vary depending on the oil's purpose and performance requirements.
Compatibility
Most automotive engines are compatible with either 10W-40 or 5W-30 motor oil. However, it is always best to consult your owner's manual to confirm which type of oil is recommended for your vehicle.
Using the wrong type of motor oil can cause engine damage, so it is important to be sure you are using the correct oil for your vehicle.
