Synthetic oil is generally preferable to mineral oils for modern vehicles. It operates better at lower temperatures because the lower viscosity of synthetic oil means it is able to flow and lubricate the engine at cold starts more easily. Furthermore, at high operating temperatures, the molecules in synthetic oil do not break down as easily, thus protecting the engine from excessive wear over time. However, manufacturers specify the most appropriate oil to use in their vehicles to ensure consumers get the best out of the vehicle. Using different oil from the manufacturer’s specification can be detrimental to the vehicle’s fuel consumption and/or its engine’s life.