Forcast for -30 F. At what temperature will DexCool protect to?

reardiff · January 28, 2019

Looks like actual air temps may be closing in on -30 F this week and from what I can tell 50/50 mix of Dexcool protects from freezing down to -34 F. Daytime highs are forecast to be -17. Any concerns with parking outside for extended period of time (few days) in these conditions? Unfortunately, I don't have an engine block heater. Never thought I'd need one living in IL, but -30 in closing in on an all time record low for the state of -36. Windchill forecasts going to -60

dieselfan1 · January 28, 2019

It should good to -40F below . I just checked mine (2018 Silverado)

Your truck don't care about the wind-chill . All that does is cool it down faster.

I'm heading to International Falls in the morning so I'm also concerned.

It was -44 F air temp without wind-chill there yesterday. Winter sucks when it's this cold.

slj2008 · January 28, 2019

27 minutes ago, dieselfan1 said:

It should good to -40F below . I just checked mine (2018 Silverado)

Your truck don't care about the wind-chill . All that does is cool it down faster.

I'm heading to International Falls in the morning so I'm also concerned.

It was -44 F air temp without wind-chill there yesterday. Winter sucks when it's this cold.

DRESS WARM - Winter Rule leave truck run. your looking at wind chill's -40 - -60 next few days . per . National weather service. Part of Canada had -75 wind chill this morning. Have Fun , STAY WARM

reardiff · January 28, 2019

Good luck with that, and stay safe. I know the water ratio effects it as well. But assuming these things come from the factory with 50/50 which is where I got the -34 number from. Never even dreamed I'd be talking about temperatures of -30 living in IL. But mother nature has a way of balancing things out, so somewhere in it must be well into the triple digits to make up for this and will end the warmest month on record globally..

Just think that at -30 if it warms up 100 degrees it will still only be about as warm as it is in my house right now.

StableO03s · January 28, 2019

New member here, replying b/c I was just researching this last night and chatting with some Canadian peeps (I also live in N. IL). I've got 3 GMTs (5.3L and two 6.0L); two have to stay outside, and the one in the garage is 'new to me' (haven't gone through it w/ a fine-tooth comb yet, but I did check the protection level once we got word it was going to be super cold). Like the OP, I heard -30F and started worrying.

If you've got 50-50 mix of Dexcool, you'll be OK. At -34F, the antifreeze can supposedly start gelling / slushy, but it can still move, and it won't expand, like straight water will.

My Canuck friends tell me they've seen -36F equivalent ('rare', per them), and they've never seen any indication of freezing. To them, -30F is something they experience fairly regularly (they do hook up their block heaters). Also, they tell me they run 50-50, not 60-70% concentration.

Hopefully, you've got an oil with a good low pour point in the crankcase. If you garage the truck, you have even less to worry about.

If you've got a block heater, hook it up. I don't, but after talking w/ the canadian guys about this, I'm no longer worried.

Oh, and the temp balance the OP mentioned...it's in Australia...around +115F for the last couple of weeks. New territory for them, too.

LSR Mike · January 28, 2019

I would worry more about the battery, just sayin'

dieselfan1 · January 28, 2019

If you're really worried about it you could start it up every 6 to 8 hours let it run for a half hour or so

Loco-diablo · January 29, 2019

UGH!! WINTER SUCKS!

L86 All Terrain · January 29, 2019

-30 to -38 Celcius (-22 to -36f) here in Canada for 2 weeks now, we get it every year. Never had an issue with Dexcool related to gelling in cold temps.

davevinc1080 · January 29, 2019

32 minutes ago, L86 All Terrain said:

-30 to -38 Celcius (-22 to -36f) here in Canada for 2 weeks now, we get it every year. Never had an issue with Dexcool related to gelling in cold temps.

Same conditions for me. I do not have a block heater on my truck either and no issues yet on my 2015 5.3.

L86 All Terrain · January 29, 2019

I am in Ontario too Dave, NW region. My phone says -43C with wind factor right now, gas trucks started fine but the diesels were not happy this morning. My shop furnace cut out on Sunday night too so I was battling that before the pipes all froze. Funny how stuff works awesome until it is life-or-death cold out, then it decides to break down.