Is anyone using the Evan's waterless coolant in their V12 XJ-S? If so, can you share any feedback? Does it keep the V12 any cooler?

Since replacing the original thermostats, my car seems cool but I'd want to do everything I can to help keep it cool.

Evans Waterless Engine Coolants - FAQs - frequently asked questions

 

Lots of opposing views on this. Here is mine:

If the thermostats are OK your car cannot run too cool. So it looks to me as though you have no reason at all to change anything. Leave well alone, say I !

Waterless coolant is esentially, chemically, 100% Glycol. Normal antifreeze is diluted glycol. The advantage of 100% glycol is NOT that your car will run cooler, rather it will actually run hotter, as 100% glycol is LESS able to transfer heat than diluted glycol, which is itself LESS able to transfer heat than 100% water! (We use diluted glycol antifreeze nevertheless to protect the engine from cold AND to use the additive package in commercial antifreeze to prevent different metals in the engine corroding and reacting electrolytically).

Although 100% glycol will run hotter, its boiling point is so high that pockets of superheated steam cannot form in the hottest parts of the engine, so the SOLE advantage (as far as I can see) of 100% glycol is this. However, if your system is good and all is functioning properly (which is MUST be regardless of which coolant you use) this "advantage" is completely pointless as these pockets will not form.

Finally, in the second world war, "glycol shields" were fitted to spitfire and other fighters, because 100% glycol leaking out of an engine at 300° F is a desperately dangerous substance. Now, while nobody will be machine-gunning you in your XJS, I cannot for the life of me see why anyone would want to have this stuff at elevated temperatures in their car. Finally, higher actual temperatures in the coolant equals higher under bonnet temperatures and higher oil temperatures, which is the last thing we XJS-ers need.

I have put on my flack jacket and await the responses!
Greg

 

Well said Greg!

The topic of waterless coolant comes up frequently on many car sites, I suppose because of semi-endorsements by either Jay Leno or the guy on Dealers Wheels.

This stuff has NO real-life benefits to any vehicles I'm aware of. It's the ultimate solution looking for a problem. The one thing it will most certainly not do is assist a car in running cooler!

BTW- I'm not interested in reopening the debate, it's all in the archives.

 

This is my favorite and perhaps the most reassuring part of your excellent and educational response.

Thank you.

 

I heard that this stuff doesn't need a pressure cap, because it never generates a pressure, because it's boiling point is so high. Is this true ?

 

I had no idea what a controversial topic this is. I'm sorry.

My understanding from the following thread is that a pressurized system will still have pressure, that all liquids expand with heat but that a waterless coolant will still heat up, expand, pressurize, etc.. but at a different rate.

https://www.jaguarforums.com/forum/x...8-83915/page1/

 

It's not so much 'controversial', it's simply brought up frequently by newer members. In each of the times that we've thrashed it, no one has really come up with valid counterpoints to justify switching. The 'no-expansion' concept is one of the first thing that gets removed from the table, once people think about it.

Oils, filters, additives and octane levels on the hand are much thornier topics. Best run and hide now.

 

In a closed system, it will generate pressure, because like all things, propylene glycol expands with temperature.

But, 100% glycol has a boiling temp of about 188C so doesn't NEED the pressure to resist boiling like the water mix does.

 

The promoters generally recommend a lower value pressure cap than the normal system. You have to have some cap to stop the stuff slopping out, and also some release device in the cap to allow for unforeseen pressure disasters... So a lower pressure cap does the job.

Greg