Is it a good idea to leave the engine running when you're not driving?

Leaving the engine running when the vehicle is not in motion is generally not recommended for several reasons. When an engine idles for prolonged periods, it leads to unnecessary fuel consumption and increases emissions, which are harmful to the environment. In addition, idling can contribute to engine wear over time as the engine does not operate at its optimal temperature, leading to incomplete combustion of fuel and the potential for carbon build-up.

Moreover, running the engine while stationary can pose safety risks, such as increased exposure to carbon monoxide in enclosed spaces and potential vehicle theft if left unattended. Overall, turning off the engine when not in use is more efficient and environmentally friendly, making it the better choice.