Ever wondered why U.S. cars use 0W-20 while the same engines overseas use 5W-30? The reason is not about engine performance, but a money-driven strategy to meet strict EPA regulations and Corporate Average Fuel Economy (CAFE) standards, which push manufacturers to adopt thinner oils like 0W-20 for improved fuel efficiency. But while this may save on fuel, it could lead to costly engine damage in extreme conditions—especially for vehicles with turbochargers or gasoline direct injection engines. Let’s dive into the full mechanics behind this decision...