[Kibwe Walker]

Originally Posted by 3Sfever

First off, we probably should agree on "terms", (as mentioned earlier). I would have thought "intake" temps as being at throttle body also.

The temps I will be referring to are the ones reported by ScanMaster, which appears to be at the MAS.

I drove a fairly long circuit this morning. The ambient temps stayed in the low 40's (F) the entire time.

Car was in garage at approx 55 deg when started. Scanmaster reported 55 going out the driveway, so that is encouraging that temp measurement is reasonably accurate. Temps rose to mid-60s and stayed there over the next 10 miles of driving 2-lane highway speeds (and occasional traffic light).

Car sat approx 20 minutes, then was started again. Engine bay was probably more heat soaked now. I forgot to check temps until moving a mile or so, but temps were in mid-80's then, and dropped to low 70's. Stayed there, for 10-15 miles of 2-lane highway driving.

Stopped to get some "fast" food at a drive thru. I did not time it, but seemed like 10 minutes. I remembered to check the temp while waiting for my food at the window, at the end of the wait. --> 103 degrees.

Temps dropped down to mid 80's on rest of trip at highway speeds.

Summary:
K&N filter, no cold wall or hood vent etc.

from cold start:
40 ambient 60s driving = 20 deg diff

after Mild engine bay heat soak:
42 ambient 70s driving = 30 deg diff

Idling for 5-10 minutes:
42 ambient 103 deg = 60 deg diff

after engine bay heat soak:
42 ambient 80's driving = 40 deg diff

I see similiar numbers but if you catch a day where it is 70 or more ambient you get 9x on a decent cruise and as high as 13x on slow cruise to stop situations.