Originally Posted by
MetroMPG
My '14 Mirage has a full upper & partial lower grille block.
I just drove it for nearly 30 minutes after a cold start at -20C = -4 F, and the engine never quite got up to normal operating temperature (low 190 F range). The highest I saw was 183 F (ScanGauge II).
If I ran the heater fan on the highest setting, the temp actually dropped a few degrees, to the high 170's.
Now, this all happened under pretty efficient conditions: mostly level country road cruising at 70-75 km/h = ~43 mph, which is not very demanding on the engine. It wasn't quite generating enough "waste" heat to keep up with the heater.
An automated variable lower grille block would have helped. I wonder what the oldest & most common cars are that had this OEM feature... might be able to scavenge parts at a junk yard.