Anti-Freeze Testing Results

Hi all,

With the hot weather upon us here in Atlanta, I too am concerned about high engine temps. So I thought I would try out a different kind of anti-freeze and T-stat just to see if I could keep the car running a little cooler than the usual 100c plus that I normally see. My car is a 95 E320 with 150k miles on it.

First, I installed a Wahler brand T-stat in the car and Mercedes coolant mixed 40/60 using distilled water. The temps. fluctuated terribly, constantly going up and down. They would jump anytime I slowed down and almost immediately drop when I was at cruising speed. This gave my aux. fans quite a workout!!!

After not being to happy with the results, I installed a Mercedes brand T-stat using the same Mercedes coolant. This immediately stopped the rapid fluctuating of engine temps. but it still would creep up and give my aux fans a work out if I idled any length of time. My guess is that the Wahler T-stat was slow to react to changing temps and driving conditions whereas the Mercedes T-stat is much better at keeping temps. gradually increasing and decreasing.

So then I tried the Havoline Dex-Cool mixed at the same 40/60 ratio using the Mercedes T-stat. This showed an immediate reduction in engine temps. Just as an example, I went for a ride today and the engine temps. never exceeded 99'C and that included quite a bit of stop and go traffic with the A/C blasting. It is 97'F outside so this was a very impressive improvement over the Mercedes coolant that I was using.

The Dex-Cool says it is Silicate free and Phosphate free so I don't see where it would hurt anything.

Any comments or similiar results out there?????? By the way, I had intended on using a bottle of water wetter but I don't think I'm going to bother now with results like what I've seen.

Dale

[engatwork]

I get the same results with the water wetter and 40% MB coolant and 60% distilled water mix. I never see the needle close the space at the 100 dC mark.

[Mike Murrell]

Dale:

I won't dispute the temp. diffs. between Dex-Cool and MB coolant; however, I have used both and I see identical temps on my gauge.

It's possible that your coolant to water ratio changed when the Dex-Cool was installed.

If you really want to see a difference, use water, 2 bottles of Wetter Water and a qt. of water pump lube. The only problem with this is you now lose the higher boiling temp. capability that you get with a 50/50 mixture.

This coolant- to-water thing is catch 22. There are trades-offs.

Jim,

This testing I did with my car was over the course of several months. Going back and forth between the Mercedes coolant and the Dex-Cool. The only thing that stayed constant was the 40/60 ratio mix. At one point I tried the water wetter with the Mercedes coolant and couldn't tell a difference.

One more thing that I observed is when I was using the Mercedes coolant, and stopped into a store for a few minutes, when I started the engine back up the temp. would soar. For some reason it doesn't do that using the Dex-Cool. I'm not sure why, but is seems that the Dex-Cool transfers heat better.

These were all just personal observations that I came up with hoping to help others that may be experiencing cooling problems with their cars or are tired of seeing temps. in the low hundreds. It might not help everyone but it sure did me.

Thanks for the replies and comments gentlemen.

Dale