Warm up or no warm up?

[MNgopher]

I'm a start it and go driver. Easy of course, until some warmth finds its way to engine internals. The only idling my cars get is to scrape ice of the windows. Might as well get any heat benefit that can be had if I'm at it.

Gotta agree with the other posters - an unheated garage generally will maintain a temp substantially warmer than outside air when at cold temperatures. The unheated garage in our old place was generally 20 degrees warmer than the outside air during the winter. The garage caputes the heat radiating from the unfrozen ground beneath it as well as any heat that dissapates from your car as it cools down. It makes a substantial difference when its real cold outside.

Now if that condition extendend for looong perod of time, the temps may stabilize between indie and out, but that hasn't been my experience in reality.

Bridge decks feeze first because they don't get the benefit of the large heat sink (source) that the earth proides under regular roads. The air in contact with both sides of a bridge surface allows them to freeze much more quickly than the road surface.

 

[XS650]

quote:

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Originally posted by mechtech:
Tosh - No, I haven't seen water freeze above it's freezing point.
Neither have you.

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It freezes because it gets colder than the surrounding air. Have you ever noticed that frost forms earlier on windows that have a good look at the overhead sky, like windshields and rear windows.

It is far more prevelant on clear nights because radiation to space isn't as blocked by moisture in the air.

 

[Tosh]

quote:

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Originally posted by V1:
I don't think I've ever heard of.... water freezing above 0c.

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Nobody has said that (but it's a good example of how internet myths get rolling). The freezing water in this kind of frost has reached a temperature below 32F, while the surrounding air temperature is still above 32F.

Obbop: Time to clean out the garage so you can park in it!

 

[slickfisher]

Unless it's very cold out a short warm up is all that is needed 15-30 seconds. The important think is to keep the revs below 3k or so until the engine reaches operating temp.

But don't start the car and immediately put the tranny in gear like my wife. GRRRRRRRRRRR.

 

[bobo]

In colder weather I let my 95 Maxima warm up for about one minute. Otherwise I let it warm up for about 30 seconds and just drive it slowly until it comes up to operating temperature. Given that it has an aluminum block, it warms up fairly quickly. I try to keep it under 3,000 rpm until the needle is in the middle of the guage, which might take say 3 miles.