Idling speeds vs heat

[BrianX128]

I'm curious about this as I have a good stretch of rush hour traffic on my way home from work when I work 7-5 that can really be a warmer on the engine. Never gotten above 220 but I'm curious as I've done the high idle mod with the resister to keep the cold advance from activating, am I better off idling low or high to keep engine temps the best there going to be in this case and also the ac will most certainly be cranked.

I feel like my temps are higher when I high idle but definitely makes the ac colder. Temps weren't exact nor were driving times though when I've tried to test it so it's kinda hard to use my results as a guide thus far.

 

[MTKirk]

All other things being equal, a higher rpm will always yield a higher engine temp. More ignitions per minute (and more fuel injected) = more BTU's of heat to dissipate. Stop & go traffic with A/C is an excellent reason to switch to electric fans, you would likely be able to lower your idle speed & still have cold air.

 

[BrianX128]

I just wasn't sure if there was a threshold where the higher rotation of the fan spinning would keep the engine a little cooler or not.

 

[jwalterus]

higher rpm = more flow from fan cooling radiator + higher flow from water pump

I've always noticed that 1200-1500 rpm cools my truck down quick if I hit over 220