Warm up before turning off?

[Captain Caveman]

Here's a question that has always bugged me: Do you need to warm a vehicle up to normal operating temperature (where the t-stat has opened) before shutting off your car engine? Meaning, if it is minus 20 degrees outside is it bad to start the motor and turn it off a minute later, well before it has reached the normal operating temp?

Does it matter if the temperatures are above freezing or below?

 

[exbass94]

Why would it be bad? What sort of bad things do you think would happen? I'm gonna say no, it's not bad to turn it off before it warms up.

 

[adsm08]

I'd say in really cold weather it would be easier on it to only run it for a moment. Not getting the metal hot and then letting it cool quickly again.

 

[Captain Caveman]

I guess the old wives tale that I heard goes along the lines of partially warming a cold engine and then letting it cool quickly.

 

[btm757]

I could see if it was a diesel but a gas motor i dont see a problem with starting it then turning it off.

 

[martin]

If you do it too many times at those temperatures you will end up with a flat battery.

 

[AllanD]

People forget that the fuels we burn are HydroCarbon, everyone knows that Carbon Dioxide and Carbon Monoxide are produced but everyone forgets about the water that is produced from all the hydrogen component.

that being said water gas condenses on the cold metal surfaces and starting wiht lube oil contamination that aids in the formation of varnishes and other contaminants (bad)
to the water that condenses inside the cold exhaust system combines with various other compounds (of sulfur and nitrogen) will rot your exhaust system more rapidly

there are sound reasons for completely warming up the engine before shutting it off.

AD

 

[Ranger Sport Honduras]

People forget that the fuels we burn are HydroCarbon, everyone knows that Carbon Dioxide and Carbon Monoxide are produced but everyone forgets about the water that is produced from all the hydrogen component.

that being said water gas condenses on the cold metal surfaces and starting wiht lube oil contamination that aids in the formation of varnishes and other contaminants (bad)
to the water that condenses inside the cold exhaust system combines with various other compounds (of sulfur and nitrogen) will rot your exhaust system more rapidly

there are sound reasons for completely warming up the engine before shutting it off.

AD

thats why ur an advisor, u do know a lot of stuff, i didnt knew that
thanks

 

[naford]

I would think you would get condensation in the oil also i heard wax build up.