AC Makes 5.0 Run Cooler?

[Ifracit]

My 2025 5.0 Lariate seems to run cooler with the AC on than when it’s off. On two occasions traveling on Interstate with ac off temp was running 205 to 210 with outside temp around 65. When outside temp warmed up to 75 I turn on ac and immediately temp drops to 190 which is what I’m used to seeing. This occurred two different times. Is there a reason for this? Has anybody else witnessed this?

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[digitaltrucker]

Maybe because a cooler engine gets better fuel economy?

 

[RcFlyer330]

Or maybe it has something to do with the grill shudders opening up when you turn the ac on.

This is just a theory. I dont know if that is what actually happens but it make sense in my head

 

[JCsTruck]

Or maybe it has something to do with the grill shudders opening up when you turn the ac on.

This is just a theory. I dont know if that is what actually happens but it make sense in my head

That makes total sense. You need the air flow for the condenser to shed the heat which also allows more air through the radiator. I bet Ford programs those shutters to stay closed as much as possible to favor fuel economy.

 

[ApolloChurchill]

I removed my shutters and it did drop my coolant temps. The shutters definitely try to stay closed as much as possible, hated it. Even parked they’d want to stay closed and now that they’re gone I can be idle after hard running and my temps drop so much quicker.

 

[XLT22]

That's normal. Ford uses the grille shutters more actively than GM or Ram do for fuel economy and thermal management. It's one of the reasons these trucks have an EPA highway rating some 5-6 MPG better than their GM counterparts although in the real world it's more like 2mpg better.

You're not hurting anything with coolant temps reporting 205-215 or so. It isn't 1985 anymore. The dash is an inferred temp anyway which is another rabbit hole to go down. The shutters will open when the engine "needs" to cool off.

 

[Davidwnuc]

Yes. Shutters open when ac is on. Same thing happens on my sons 2017. You can watch trans temp drop when you turn the ac on.

 

[MikeNH]

Not just shutters. AC commands the cooling fan on to get air flow across the condenser which of course helps cool the engine. Without it, my 2.7 seems to allow temps up to like 215* or so before they kick on.

 

[XLT22]

Not just shutters. AC commands the cooling fan on to get air flow across the condenser which of course helps cool the engine. Without it, my 2.7 seems to allow temps up to like 215* or so before they kick on.

The fans aren't doing anything to cool the engine running down the road at 60mph. When I'm running AC off I usually see 205-207 at steady cruising.

 

[Billflangjr]

Or maybe it has something to do with the grill shudders opening up when you turn the ac on.

This is just a theory. I dont know if that is what actually happens but it make sense in my head

Yes grill shutters , I’ll call them. I have read in the Tremor forum to remove 2 or 3 makes it run cooler ! I would like to do that. Do we have more information on that?? They say it’s easy to do.

 

[ApolloChurchill]

Yes grill shutters , I’ll call them. I have read in the Tremor forum to remove 2 or 3 makes it run cooler ! I would like to do that. Do we have more information on that?? They say it’s easy to do.

It’s pretty easy you just bend them out at the pivot. I took all but the ones attached to the motor off on mine for needed radiator clearance.

 

[XLT22]

Yes grill shutters , I’ll call them. I have read in the Tremor forum to remove 2 or 3 makes it run cooler ! I would like to do that. Do we have more information on that?? They say it’s easy to do.

There's quite literally zero reason to do that. Your engine doesn't need to run "cooler" because it's not hot running at 205-215. Especially don't touch the intercooler shutters if you have an Ecoboost. They're necessary to prevent condensation.

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