Combustion engines have many moving parts that will heat up to incredible temperatures without a lubricant. Your engine’s lubricant is either conventional or synthetic motor oil necessary to keep the moving part lubricated, moving freely, and at a cool relative temperature. Engineers have yet to develop motor oils that can last forever as they will all succumb to thermal breakdown with enough mileage. Oil changes are necessary engine maintenance that cleans out the broken-down poorly lubricating and introduces fresh oil of peak viscosity.
