The main difference between 10W-30 and 10W-40 motor oil is that 10W-40 has a higher viscosity, which means that it will remain thicker at higher temperatures than 10W-30. Viscosity means a liquid's resistance to flow, and normally a higher viscosity is a good thing for oil, as it acts as a better lubricant and creates a stronger seal.Continue Reading
The viscosity of an engine oil is measured at two different temperatures: zero degrees Fahrenheit and 212 F. The first viscosity reading at zero is represented by the number in front of the W, meaning that both 10W-30 and 10W-40 oil have the same viscosity when cold. The number after the W indicates the viscosity at 212 F, with the number being higher the more viscous the oil is at high temperatures.
While both 10W-30 and 10W-40 are perfectly suited for use in warm environments, many experts recommend switching to a 5W-30 during the winter. This is because it will be slightly thinner at cold temperatures, which allows it to flow more easily through the engine. If the oil is too thick, it can make it difficult for the engine to start and run. This is turn can cause lowered fuel economy and can possibly damage the engine over time.Learn more about Engine Oil
Synthetic blend motor oil is more effective than regular oil because it lasts longer and can withstand higher temperatures without breaking down. Synthetic motor oils can improve vehicle horsepower and efficiency because they produce less resistance in an engine than regular motor oils.Full Answer >
"15W40" refers to the viscosity grade of a multi-weight oil, where 15W refers to a cold grade of 15 and 40 refers to its viscosity grade at running temperatures. The higher the viscosity grade, the thicker the oil is, which affects its lubrication ability, heat capacity and flow.Full Answer >
The symptoms of water in motor oil include presence of bubbles, residue and thick oil on the dipstick, and emission of smoke from the vehicle's tailpipe. In addition, the dipstick has a sweet odor, the level of coolant decreases continuously, and the coolant and oil mix to form a milky fluid.Full Answer >
Full synthetic oil is made differently from conventional motor oil, and vehicles that use it require fewer oil changes than those that use conventional oil. Drivers who put synthetic oil in their cars also notice less wear and tear on their vehicles.Full Answer >