Motor oil is an essential lubricant. It's main function is to lubricate the moving parts in your engine, but it also cleans, inhibits corrosion, and cools the engine by carrying heat away from those moving parts. For years, the accepted interval for oil replacement and filter service has been every 3 months or 3 thousand miles. Improvements in oil chemistry and engine design technology have allowed for longer oil-change intervals; typically, anywhere from 4,000 to 10,000 miles or more for most vehicles depending on the specific type (full synthetic oil versus synthetic blend). Over time, oil can break down as a result of the higher operating temperatures of today’s smaller, higher revving engines. When this occurs, the oil becomes less effective and friction may increase resulting in excessive and premature wear. Dirt and other contaminants may build up in both the oil and oil filter as well, creating sludge - also known as “gel.” Failure to follow the recommended service intervals provided by the manufacturer may cause your engine to work harder eventually leading to premature wear and possible engine failure. From a safety standpoint, failing to change your oil isn’t likely pose a problem for you or other motorists. But, from an environmental point of view, maintaining your vehicle according to the manufacturer’s recommendations and your current driving conditions will result in a vehicle that will run better with lower exhaust emissions and a smaller carbon footprint.