Ask HN: Why do people leave their engines running while stopped? | Hacker News Reader

Ask HN: Why do people leave their engines running while stopped?

2 pointsYeGoblynQueenne6 comments

There's a van outside my house right now, that's been parked there for some five minutes with its engine running. I can see the driver from my window, he's having a sandwich and filling in something on a clipboard. It's 13:00 in the UK, so he's taking his lunch break, I presume.

This sort of thing happens all the time. Taxis do it, vans do it, private vehicles do it. It's like, once or twice a week just outside my house so it must be a very, very common thing. And not on lunch breaks only- it happens any time of day.

What the hell is up with that? I mean, OK, climate change is of no concern (we can all breathe underwater, after all) but isn't there, you know, a cost associated with keeping your engine running?

Why do people do this?

(Note: I don't drive; I might be missing something.)

In colder weather, we do this to keep the heat on. Aside from that, I've always been under the impression that starting and stopping the engine, unless its specifically designed to do that like in the case of cars that stop the engine at red lights - adds additional unneeded wear and tear to the engine.

turning off an engine for 3 or 5 minutes, assuming it was warm, won't make the engine loose to much heat. Turning it off for a half hour, in the case of waiting for someone to get out of an appointment or store - would make the car loose enough heat that the heater will need time to warm up again upon starting again. Not a huge deal; just an inconvenience.

I've also been told in bad snow storms, don't turn off the engine if your just waiting, for fear snow or ice might cause it not to restart but I don't think this is an issue on any modern cars (> 2000)

Seems to me this happens most often when it is not the driver who is the one paying for the fuel.

Usually the fuel usage is very low per hour if parked. The advantage of having the engine running are heating or airconditioning and sometimes the fancy media system that might go into low power / radio only mode when the engine is off.

Something interesting on the radio, maybe? Or perhaps it's cold outside and he likes having the heater on?

I'm assuming it is for heat or air-conditioning.

Makes me crazy when I see this too.

I'd guess that too but it's not that cold where I am (12° C) and anyway I've seen it on the mellowest summer nights where no heating or air-conditioning would be required.

Glad to see it's not just me :/

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