Funny you mention this. After following the subject post. I decided to check the antifreeze level. I have a fairly new and good electronic refractor anti freeze checker. Could not get a accurate reading on the Dex-Cool mixture. Went thru the scales, numbers were all skewed. Cross checked it against some machinery and other vehicles using different coolants, all checked out correct. So the question, does anyone know with exactly what tester, will provide solid Dex-Cool readings. I believe its a hybrid organic acid tech base fluid.

 

I looked at the MSDS sheet. It is still ethylene glycol.

 

^^^^
Probably relates to the additive packages!

Have some fun stories about Prestone Antifreeze!

SIDEBAR
Worked for the Industrial Gas Division of a Chemical Company that made ethylene glycol. There was a Consumer Products that sold Prestone.

We had a huge new R&D facility in Tarrytown NY. I was in welding R&D and the Consumer products folks and some other Divisions were there as well. Recall they were asking for volunteers to test their "new" Prestone with sealent. One of our R&D guys volunteered and they put holes in his rad. The stuff did seal the small leaks! Didn't say what it was but they started to sell it. . My group had invented and patented a vertical welding machine that crawled up two plates. In fact is was called the Electroslag Plate Crawler (Electroslag is a welding process, if interested you can goggle.)

We sold a number to shipyards to weld plate from 1/2 inch to 1inch thick in one pass as it crawled up a square butt joint with about a 3/4 inch gap. I remember getting a call from the welding engineer at Newport News Ship, who I knew. He said winter is approaching so what should we do with the water cooled copper shoe cooling system. The shoes retained the molten metal. Thought an said use Prestone! He called a few weeks later and said the water flow had reduced to a trickle. The copper cooling shoes had very narrow cooling passages so their were no pockets of stagnate water that could boil. Molten metal was on one side at ~2500 F and copper melts at ~2000F. But needed to keep that interface surface even cooler.

I went to the Consumer Products R&D folks and said what is in that "new" Prestone? They told me asbestos fibers! As the long fibers try to go through a hole some get stuck. Others get tangled with the first few and soon the hole is plugged. That is what was clogging our water cooled copper shoes. Call the engineer and apologized and said please switch to plane ethylene glycol!

Trade Mark: The other fun issue was when I moved to Corporate Office and started a welding market development group. We produced a monthly new letter that was sent to ~3000 distributor and our own Regional sales and engineering folks. Had to have it approved by 5, yep 5 attorneys.

1. Our Division attorney who mostly checked for FTC issues re prices. There were only 3 suppliers and had to be sure no mention of price as that could be called signally. Frankly we were the market leader and when we raised prices the other two did as well BUT had to be careful!
2. A Corporate Safety and Heath attorney (read product liability.)
3. A Corporate patent attorney
4. A Corporate Trademark attorney.
5. A Corporate Commercial attorney.

This was before emails and IF I waited for the drafts to get approved would never make the printer deadlines. Learned best to had carry when we needed in a hurry, Became very knowledgeable about Trademarks from those discussions! Before I interrupted and asked for an approval would discuss what was in interest to them! The trademark attorney had a Yellow gallon jug on his shelf. It was a antifreeze being sold by Amoco. Did not have a name like Prestone BUT also had the Amoco name only in small print on the back. Yellow was not their corporate color, etc. Learned first, Trademarks are NOT given to protect the company. they are to protect the consumer from being fooled that the Coke shaped bottle by XYZ was NOT the product they thought they were buying. He brought a lawsuit against Amoco for using a Yellow jug the same size and shape as Prestone. He defended his position with a number of focus group results. Folks were asked after being shown different jugs what these different products were. Many said the Yellow Amoco jug was probably a new Prestone product. He won. They had to change their jug color!

 

Test results, Meter AMR317 Digital Refractometer

Scale 1 S01 window cleaner antifreeze setting -50.4 F

Scale 2 S02 Ethylene Glycol -11.5 F

Scale 3 S03 Propylene Glycol -.09

Scale 4 S04 Urea 27.4%

Scale 5 S05 Urea Refractive Index 1.3747

Under the assumption that the cars are shipped 40/60 mix, for -18. None of the measurements are within range. Data shows Dex-Cool seems to be a hybrid mixture with organic acid tech.

 

Used a Prestone arrow guage that says it good good for DexCool. On my 2021 GMC Sierra it showed -45F. On the 2021 Corvette -5F. Both are DexCool. GM is not filling Corvettes with a 60/40 mixture apparently. More like 65/35. Beware of subzero temperatures.

 

Good info, thank you. Now we need a few more comparisons. I have thus far been unable to locate a absolute Dex-Cool certified tester. I'm questioning, if standard testers can read the new dex-Cool. Maybe your tester is reading right, maybe mine is, maybe not. Need more test to get a baseline. Interesting that your Sierra read good and the Vette didn't.

Ok who has a jug, of new GM premixed Dex-Cool hanging about for a test ?

 

Burst point of a 60/40 mixture is -50F. As long as you don't drive when temperature is below -5F the engine won't be damaged until it hits the burst point. Considering the better cooling capacity, I will keep the mixture as is.

https://www.shoptalkbyindmar.com/ser...tection-levels