What are the effects of forgetting to turn off a BMW for several hours?

[BradyRose]

Forgetting to turn off a BMW primarily affects the engine. If the vehicle remains parked with the engine running for an extended period, the engine will operate at low RPM for a long time, increasing carbon buildup on the pistons and valves. This can lead to unstable idling or other adverse effects, and in severe cases, it may even impact the engine's lifespan. Below are the relevant details: 1. Car engine idling: Prolonged idling is not advisable. During idling, the engine operates at low RPM, which can result in increased fuel consumption and incomplete combustion, leading to carbon deposits that significantly damage the engine. 2. Engine wear: If the vehicle idles overnight, the most immediate effect will be noticeable fuel depletion, followed by an increase in exhaust fumes inside the cabin. It is recommended not to enter the vehicle immediately; instead, open the doors to allow air circulation for a while. Other effects are not visible to the naked eye, but the more significant ones include increased engine wear and carbon buildup. If the vehicle has no other issues, these effects should not cause major problems.