Cooling system mixture why?
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Cooling system mixture why?
So the recommended mixture is 40% DEXCOOL and 60% water that gives protection to -18F, BUT if ambient is below -18F use 50/50 mixture.
Which begs the questions 1) what does factory put in and 2) why not always 50/50?
Which begs the questions 1) what does factory put in and 2) why not always 50/50?
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Jun 8, 2021, 03:49 PM
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Because water does a better job at heat transfer than Dexcool.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
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Originally Posted by Jeff V.
Because water is cheaper than DexCool and that makes the cost per car just slightly cheaper. Add that up over 30,000 cars and it turns into real money.
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From: Bay Area CA
Because water does a better job at heat transfer than Dexcool.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
Last edited by Mike's LS3; Jun 8, 2021 at 03:56 PM.
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Edit: Mike was faster than me, that's what I get from keeping my edit open while eating lunch
Last edited by c_r_h; Jun 8, 2021 at 04:02 PM.
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Because water does a better job at heat transfer than Dexcool.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
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E-Ray, 3LZ, ZER, LIFT
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From: NE South Carolina
Because water does a better job at heat transfer than Dexcool.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
In my boosted C6 I ran 70/30 Distilled water/Dexcool with Red line water wetter and never had an overheating issues. My car ran Cooler!
Yes, the factory fill in a C8 is 60/40 water/Dexcool, a smart move by GM. It has to do with cooling performance not money.
Yep! Spent a lot of time on the cooling system when I built my '34 Ford ProStreet Rod with an 8.2 Liter BB. Has a '34 Ford size rad (mine is thicker and aluminum but forced to be the same height and width) cooling a much bigger engine than Henry used! I use 33% coolant and 67% water with has a higher boiling point. Works for me in NE SC as with the car garaged and never gets to 0F. The boiling point at 15 psi is higher. Water also has a higher heat capacity. I also use Red Line and have a mechanical as well as two electric fans that come on when idling or driving slowly on 100F days. The other key was ignition timing at idle. I use manifold NOT ported vaccum for the advance control but that's another story on another page of my website!Pic taken of part of a website page re Street Rod cooling:
Last edited by JerryU; Jun 9, 2021 at 09:01 AM.
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From: Grimes Iowa
I bought my C8 from a dealer in Texas and I live in Iowa, my car tested at 5 above when I got it. I took it to a local dealer to get it down to minus 20 and was charged $300, they said they couldn't just drain down a gal and add. Texas dealer offered to reimburse me but I said it wasn't necessary. I think all C8's should come from the factory with a 50-50 mix.
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One day when the C8 is in surplus, will dealerships in places where temps drop below -18F know to keep the cars indoors? And do owners today know of this? Should be a huge warning sticker, not buried on page 246.
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Originally Posted by Don Wallace
I bought my C8 from a dealer in Texas and I live in Iowa, my car tested at 5 above when I got it. I took it to a local dealer to get it down to minus 20 and was charged $300, they said they couldn't just drain down a gal and add. Texas dealer offered to reimburse me but I said it wasn't necessary. I think all C8's should come from the factory with a 50-50 mix.
Just curious what made you even think of testing?
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I bought my C8 from a dealer in Texas and I live in Iowa, my car tested at 5 above when I got it. I took it to a local dealer to get it down to minus 20 and was charged $300, they said they couldn't just drain down a gal and add. Texas dealer offered to reimburse me but I said it wasn't necessary. I think all C8's should come from the factory with a 50-50 mix.
I don't understand why your dealer couldn't adjust the ratio, probably just didn't want to do the math. If the test was valid then it came miss-filled from the factory and correcting to 60-40 should have been covered under warranty (which it sounds like was offered). However, I think it is unlikely that it was filled with the wrong ratio from the factory. If it was then there are probably a lot more cars affected than just yours.
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From: Grimes Iowa
I used 2 testers to verify amount. Dad taught me YEARS AGO to test every car each fall and a 50-50 mix gives you a little extra protection if you had to add a little water or if a dealer did. I suspect the dealer never checked before delivery.
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Originally Posted by Don Wallace
I used 2 testers to verify amount. Dad taught me YEARS AGO to test every car each fall and a 50-50 mix gives you a little extra protection if you had to add a little water or if a dealer did. I suspect the dealer never checked before delivery.
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From: Garden Valley CA
My experience with the hydrometer type of coolant testers is they give ballpark figures but aren't extremely accurate for coolant freezing point since they are extrapolating from specific gravity and are subject to temperature errors, etc. I have no experience with the electronic types.
It would be interesting to see what the same testers measure under the same conditions on a known 60-40 mixture.
If the ratios are truly off then I suspect there are lot of cars out there with bad water-coolant ratios. I doubt that the ratios are made individually for each car.
It would be interesting to see what the same testers measure under the same conditions on a known 60-40 mixture.
If the ratios are truly off then I suspect there are lot of cars out there with bad water-coolant ratios. I doubt that the ratios are made individually for each car.