Using concentrate Dex-Cool

[rcarsey]

So during my recent annual, I experimented with filling the coolant system with Dex-Cool concentrate instead of 50/50 mix. Some around my airport say I accidentally bought the wrong stuff at the auto part store.. but I'm going to call this an experiment.

It wasn't the end of the world, but temps were a good 30F hotter. Ground taxi was more difficult -- temps would rise very quickly.. almost as if it were a 100F day instead of 70F (see 2:30 on the chart). Nothing unexpected -- but now you know some numbers to go along with it. During the post-annual test flight, I did notice that the temps were a bit higher than I would have expected for a pleasant day.. it took me some more time to figure out what the cause was though. I initially checked for air in the radiator (it was 100% full).

I ended up flushing the system with 50/50 pre-mix.. then refilling it with 50/50. "Why do a job once when you can do it twice?"



This is a 73F ambient day (100% DexCool):



And a 76F ambient day (50/50 mix):

 

[docjjrmd]

Rob; nice "experiment", just a reminder to folks that distilled water should be used to dilute the concentrate, not tap water. I've found the savings of using concentrate plus the cost of distilled water pretty much is a wash over just buying the pre-mix. Pre-mix equals less hassle even though it costs a few cents more. Water is hard to beat as an energy transfer fluid. Nice graphs by the way.

 

[CTCole]

Thanks for sharing that, Rob! It's very nice to see real data.

p.s. re heat capacity of water: my intro chem prof once said "the more we learn about water, the weirder it is"