[gamblor956]

You two are talking about different things. Frye is talking about warming the engine compartment; Epic is talking about warming the passenger space. You can warm the engine compartment more efficiently without idling by driving at low RPMs for the first few minutes; however, idling is as (or almost as) effective as low-speeding driving at warming the passenger area.

[EpicEng]

>however, idling is as (or almost as) effective as low-speeding driving at warming the passenger area.

Again, twenty years of turning the car on, going inside for 15 mins, and coming out and sliding into a warm car.

I'm not anywhere near knowledgeable enough to explain the details. I am fairly certain however that I was not hallucinating this throughout my entire childhood and young adult years.

[tom_]

The other advantage of idling is that when the windscreen is misted up, it doesn't matter that you can't see through it!

You can wipe condensation off, but I've always found it has a tendency to reappear quickly. Perhaps I'm wiping wrongly, but the only solution I ever found to work reliably is to leave the aircon and windscreen heater running until the inside of the windscreen has warmed enough to prevent immediate reoccurrence.

That's meant idling the engine in every car I've owned. Cabin heating never seems to run at full blast unless the engine is powering it...

[kw71]

> however, idling is as (or almost as) effective as low-speeding driving at warming the passenger area

No. The engine, and thus the water, will heat faster under a driving load.