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 about Engine Oil
The difference between 10w-30 and 5w-30 oil is the thickness of the oil during cold weather conditions, 5w-30 being the thinner of the two and therefore recommended for colder operational climates. Engine oil is rated on a viscosity scale by the Society of Automotive Engineers, which determines its cold- and warm-weather rating; the cold rating is indicated by a “w” for winter.Full Answer >
Some of the disadvantages of oil are that it is a nonrenewable resource and creates air pollution. It also is often produced by countries who are unstable politically, and it can be harmful if spilled in the ocean or some other wildlife habitat.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 >
The additives that manufacturers add to motor oil break down over time, making oil changes necessary, according to HowStuffWorks. The oil also picks up dirt and debris from the wear of the engine. While the filter removes foreign material for a while, if it gets plugged the oil bypasses it.Full Answer >