My experience is with $EE '(94 & '95).
'vettes make use of a separate scalar: 'Fan Vehicle Speed Boundary' in TunerPro, or 'Fan Hi/Lo Vehicle Speed Threshold in TunerCAT.
The vehicle speed boundary / threshold is 0MpH, so anything OVER 0MpH uses the higher speed fan-on settings.
Although GM did not bother to use this feature with F- & B-cars, they can also use this feature by specifying different 'High' fan-on settings.
To answer your 2nd question:
examine oil & coolant temps while cruising on the highway, then use the fan-on settings to maintain similar temps in stop'n'go traffic.
If the coolant is clean & the radiator heatercore & cooling fans all work properly, I see no reason why the coolant should get hotter than
221°F / 105°C.
I prefer lower temps - I typically turn on the primary fan @ 203°F / 95°C & the 2ndary (meaning both) @ 212°F / 100°C (coolant temps).
Bookmarks