Another reason for better summer mileage, and a question.
 

Go look at a graph of IAT resistance compared to temperature... ;)
https://www.yotatech.com/~corey/tech/dr_z_ect/1.jpg
On a semi-related note, does anyone know the approximate relationship between outside temps and IAT temps for their vehicle at a steady cruise. For instance, if it's 80F outside, what would the average IAT be? 10F increments would be great! :D

It was 50*F outside today and the Geo's IAT was reading anywhere from 60-100*F. However I found virtually no difference in the amount of GPH required to keep a constant speed no matter what the IAT reads (whereas outside temperature obviously plays a big role).

Thanks Peakster, that's exactly what I wanted to know. theclencher, if I wasn't planning on replacing the tranny in the pickup, I'd run synthetic in that too... at 20-50F it's slow, heavy, and grinds unless I'm very, very, very careful.

My intake temps are Identical to outside temps after about 10 miles or so of steady speed.
Once you slow down and or stop the temps go up, warmer IAT does help when its real cold.

With my intake open my outside temp and IAT are almost identical during normal cruise or regular acceleration the only time I see it go way up is under extreme acceleration. My intake is directly behind a lower passenger side grill.

My IAT is usually 10 degree hotter than ambiant temperature at cruise.

My IAT is usually what ever the outside temp is +40 degrees F

On my car IAT would stay within 5* of ambient when the car was first started and driven as long as I kept moving. As soon as I stop the IAT would start to rise as much as 50* higher than ambient. The longer I was stopped and the more stops there were, the higher the temps would climb. Even getting on the freeway and cruising at speed for 30 min would only lower the temps slightly.

Why are you asking? Warm intake project? pot mod?

I have found my iat temps are real close to ambient air temp when at steady speed.

I forgot to mention that I have a belly pan. At cruise I'm 10 degress hotter.