I've never seen any rigorous scientific tests that show Water Wetter or any other cooling system additive either reduce coolant temperature or boundary temperatures in systems that run an OEM recommended antifreeze within the OEM recommended concentration range.

For race cars that don't run antifreeze, some kind of corrosion preventative/water pump seal lubricant additive is called for, but that's a completely different application than a street legal car that sees either regular or occasional use and uses the OEM recommmended antifreeze and mixing ratio.

OEMs design cooling systems for the heat capacity and convective heat transfer characterisitcs of a 50/50 blend of ethylene glycol and water, which provides freeze protection down to -34F and boiling protection to 265F with a 15 psi cap. Then they test everywhere between the arctic and Death Valley.

Freeze protection down to -84F is available with a 70 percent glycol solution, but this concentration is usually not recommended unless you anticipate temperatures this low, and if it gets that cold you won't have to worry about the lower heat capacity than a 50/50 blend.

The vast majority of anecdotal evidence I've seen from those who have reported using cooling system additives is basically - "made no difference" and like I said, I've never seen any rigorous scientific tests that back up any of the performance claims by manufacturers or some users or these products.

Duke

. . you don't believe the chart(s) posted by WW showing the improvement in cooling. I guess they are 'lying' according to you. It clearly shows the difference using it vs various ratios of af and water.

I've used both WW and am currently using PI. As sort of an 'anecdotal' experiment, I purposely added distilled water (always use that) and MB af at a ratio of 65/35% (w/af) without any additive. The next day (the temps were the same; HOT!), I added PI (1-1/2 oz/ gallon) and you could immediately see the difference as reflected on the temp gauge in the IC. Of course that, to you, is anecdotal but that's what I call a 'real' world test! Kinda makes you believe the charts they have published.

BTW, what makes anybody think that you are an expert in af, coolant additives or anything else for that matter. For fact, the PH of MB af is designed to be neutral which is not true for Zerex. And where does it say that it's recommended for MB?

Does one need to use WW or PI?? I guess that decision is up to each individual but the fact is that both do work as advertised.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

I view vendor supplied "tests" with a jaundiced eye.

Zerex G-05 labeling states that it is the same chemistry as used in "all Mercedes vehicles". This I am willing to believe at face value. If it were not true, Valvoline would have heard from the DB legal department by now, and a name brand like Valvoline would not want their good name compromised by legal action from a major OEM - doesn't make for good PR or vendor relations, so labels from well known brands that such and such meets OEM specs can usually be counted on to be true.

All OEMs have specifications that various fluids must meet. They are usually very comprehensive and include a number of industry standard tests from organizations such as ASTM, and in the case of antifreeze, specific tests that each OEM develops.

Once you pass the OEM test suite, which is usually conducted and certified by an independent test lab, you can claim your product meets the OEM spec. This is a lot different than a fluid vendor coming up with their own test and posting the results on their web site.

Duke

Maybe there is a benefit from the WW/PI additive, if so, it cannot be seen in the charts. The 9 sec. difference shown is for water with WW vs. a 50/50 mixture of water and glycol. If you compare apples with apples, that is water with water + WW there is practically no difference. The same is true if you compare 50/50 mixtures with and without WW. Clearly the 9 sec. difference is due to the presence of glycol. Since there is so little difference due to the WW you might as well use water alone. I think.

JL

. . water that's the 'magic' ingredient in the 'cooling' formula. But you would be very unhappy with a failed radiator if you just used water only. Someplace (maybe it's here) there's post showing pics of just using water w/o some additive to prevent corrosion. It ain't pretty!

As you now see, that's why I use 35/65% ratio: it's the "water" plus PI that makes a big difference.

Most problems that I've seen is the af/w ratio is around 75/25; great for Alaska but not too good for So Cal. Adding WW or PI to that mixture would indeed get the comment ". . . made no difference".

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

I was not suggesting to use water alone. My point was that the charts show that adding WW (or PI I guess) has little additional cooling effect, and therefore is an unnecessary additional expense. There may be other benefits not shown on the charts and since I have not used the stuff I cannot comment on that. Other that optimizing the mixture ratio as you suggest, the only thing I think would be useful is to keep the radiator passages free and clean.

Best regards,

JL

For what it's worth I tried WW once in my 300D which was running a little hot with old (green) antifreeze. I did not notice any difference in operating temperature. After flushing the system acouple of times and putting in a 50/50 mix of MB antifreeze the temperatures went down. I have not tried adding WW to the correct antifreeze mixture, and don't plan to.