The difference between 5w-20 and 5w-30 oil is that 5w-30 oil has a higher viscosity at its operating temperature. Viscosity is the term used to describe the thickness of a substance, in this case oil, where a higher number indicates a thicker oil.Know More
Oil viscosity varies inversely with temperature. This means that as the temperature goes up, the thickness (viscosity) of the oil decreases. To use this knowledge in an automotive application, it is important for an oil to be thin enough to spread quickly when a cold engine is started, yet it should not become too thin once the engine reaches its operating temperature. An oil with the rating of 5w-30 is a multiweight oil that will act like a 5-weight oil, which is very thin at cold temperatures, while maintaining the thickness of a 30-weight oil once the engine reaches its operating temperature. This protects the engine from wear at both temperature extremes.
The invention of the modern multiweight oil is made possible by the addition of polymers, which coil up at cold temperatures and mimic shorter molecular chains with a lower viscosity. As the oil's temperature rises, these polymer chains begin to unwind, increasing the effective length of the molecular chain and thereby increasing the viscosity.Learn more in Engine Oil
The two oil types differ in their high temperature viscosity, and 10w40 is thicker than 10w30 when it comes to high temperatures. Before multi-grade oils were formulated, car owners typically used 10w30 for its wintertime flow properties, while relying on the 10w40 for the summertime when temperatures warmed up.Full Answer >
Most car manufacturers suggest an oil change between 5,000 and 7,500 miles. The best way to determine how often a car’s engine oil should be changed is to refer to the owner’s manual.Full Answer >
Oil should be changed in the interval specified in the vehicle's owners manual. Among 2013 model vehicles, the oil change intervals can vary from every 7,500 miles in some cars to as high as 15,000 miles in others. These are high intervals are because of advancements in oil and vehicle technology.Full Answer >
PAG oil is a synthetic compressor lubricant used by original equipment manufacturers in their R134a automotive air-conditioner systems. PAG oil stands for polyalkylene glycol oil.Full Answer >