I have a Mazda 6 2.0 (2018) as a second vehicle and due to the lockdown, I haven't been driving it.

Over the weekend, I had the "bright" idea of starting the car and letting the engine come up to operating temp and idle for a bit. However, instead of waiting in my car, I left the engine running to warm up, while I went to prepare my breakfast. For the life of me, I can't remember if I went back subsequently to switch off the engine. I did take the car fob with me when I left it.

On the next day, when I remembered I may have forgotten something, I went back to my car. Well, it wasn't still running. I started it up and it seems to run fine. Fuel level is fine and engine oil seems ok.

Question is, if I did leave the car idling (without the car fob in proximity), would it have stopped on its own after awhile? I can't be the only forgetful person who has done this.

Thanks!