When it comes to maintaining the health and longevity of an engine, one question that often arises is: at what specific percentage of oil life remaining should one consider changing the oil? Is it advisable to adhere to conventional wisdom that suggests changing the oil around 15% oil life left, or could it be potentially beneficial to wait until the oil life dips down to 40%? How do factors such as driving conditions, vehicle make, and oil type influence this decision? Moreover, can one truly ascertain the optimal moment for an oil change by merely relying on oil life indicators or should one consider a more multifaceted approach, encompassing aspects like oil quality and vehicle performance? What implications do these percentages have on engine efficiency and overall performance? Thus, when pondering this crucial aspect of automotive maintenance, what is the most prudent course of action regarding oil change frequency, based on the percentage of oil life remaining?