Ambient Outside Temperature (Hi Temps)

[silverbullet]

How much does the ambient temperature (hi temperatures not the low temps) affect the temperature of the oil? Example, when the outside temperature is 70degF vs. 100degF, how much does that affect the temp of the oil when the car is "at operating temperature"?

This comes to mind as most of us out here in the west U.S. is experience a heat wave. Yesterday's hi temp was 108degF in my area.

 

[JAG]

This thread has an answer...near the bottom of the first post.
http://theoildrop.server101.com/forums/s...part=1&vc=1

 

[Laminar Lou]

Thanks for the find Jag. I thought I read most of Mola's articles but I must have missed that one.

 

[mark pruett]

In other words, it doesn't really matter much.

According to the bottom of MolaKule's article, the difference in oil temperature going from ambient temperatures of 90 degrees F to 110 degrees F is slightly less than 6 degrees F.

(32.2 C -> 43.3 C = 11.1 C = 3.3 C oil change = 5.94 F degree change)

 

[CBDFrontier06]

I think this may affect air-cooled engines a lot more than water cooled. On cold days, my 74 Beetle never got much past 200 degrees on the highway, but the last 30 mile trip I took in it (Plano to Grand Prairie) in 95 degree heat resulted in 240+ degrees on the oil temp guage (dangerous for a Beetle).

 

[mechtech2]

Ambient temperature doesn't have a big effect on coolant/water temps, but DOES have a big effect on oil temps.

 

[silverbullet]

Good find Jag. Thanks.

 

[Gary Allan]

Load has more impact then ambient temp in my observations. YMMV due to any number of factors (pan, airflow, etc.) ..but I've seen only a slight indexing of oil temps coupled to ambient in non-exchanged events. What's odd is that the terminal mileage for normalized temp (typical peak in the normal highway event) isn't altered by ambient temp all that much. From below freezing to the major plateau where the rate tapers off was the same 9-10 miles for me (155-165f) ..while the final ticks still occur at about 13-14 miles (around 210f).

As I said, YMMV.