Dan Dan the Heater Man...

Okay.  I just got back from a 250 mile jaunt today.  Ambient temp 17 
F (that would be 8 C).  At this high of an ambient, my heater was 
scorching (I didn't carry my digital thermometer today) on low speed 
and what I'd call 'hot' on highest.  Now, this is 18 F degrees hotter 
ambient than my last report and subjectively, the heater output was 
AT LEAST 18 degrees hotter, possibly more ( I should just shutup 
until I use the digital again).

Any fizzle-cists out there care to interject?  Would the temp 
increase vs ambient temp be on some sort of curve?  If the heater 
core adds 100 degrees at -20, obviously it's not going to add 100 
degrees at 120 ambient....  hmmm we need data.

inquiring geeks want to know