Coolant additive

Has anyone heard of a new coolant additive that helps increase the cooling ability of the coolant ??

Beyond the decades-old Water Wetter?


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Does it work ? just add it to the current coolant ?

Kinda: not going to buy you much. Better to ensure the cooling system is up-to-snuff.

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Did you mean Evans, maybe?

That decreases cooling ability.


honestly, from what I’ve taken from classes in physics long ago there doesn’t seem to be too much room for improvement.

In a cooling system like in our engines the heat produced in the cylinder head is absorbed by the inflowing colder liquid and via the water flow transferred to the colder parts of the engine and finally the radiator where it is dissipated to the surrounding air.

The medium that is used for the transport of heat has two qualities critical for its task: one is the ability to quickly absorb and dissipate heat. In this respect media are different. You may have burnt your tongue or gums on gratinated tomatos or zucchini. That was (probably) not because they came from the oven so hot, but because these plants dissipate heat much faster than the pizza bread underneath. This property of the coolant medium is described as heat transfer coefficient. It may be influenced by additives. However, the smaller the difference in temperature between the hot medium and the coolant medium becomes the less critical the heat transfer coefficient becomes.

The second factor for the amount of heat that can be transported away is the heat capacity of the liquid medium. As per Wikipedia water has a heat capacity of around 4.2 kJ/(kg·K). I’d guess that additives will change this only marginally. Switching to engine oil would even reduce the heat capacity by over 50 %.

Water wetter only claims that the production of steam bubbles at hot spots in the engine that may reduce heat transfer is reduced. Maintaining the correct pressure will have a similar effect.

So, if your otherwise functional cooling system (sufficient coolant, pressure, flow) is insufficient it might be that either your engine produces too much heat (i.e. burns too much fuel: increased power? internal resistance? poor engine tuning?) or that your radiator doesn’t dissipate the heat from the water to the ambient air.

Good luck


75 XJ6L 4.2 auto (UK spec)


My process over the decades. Glycol and distilled water.
Aproximate 50/50. Best a tad rich. My view. Others say not quite. but, it’s been decades that I lived in really cold clime where freeze was a risk…

I view the snake oils with cynicism.

The miracle tests are usually flawed…


A third quality is viscosity. Water has the lowest, ethylene glycol mixtures next, and Evans the highest. Cooling efficiency improves as the flow of coolant through the system increases (more liters per minute). Flow is inversely proportional to viscosity, plus viscosity adds to the total heat produced by the engine.

Interestingly, this is the only claim of Evans, too. Evans probably does a perfect job in this regard because it doesn’t vaporize at all. But (as mentioned before) it cools less and the engine runs hotter (both lower eat capacity and higher viscosity contribute). Some argue that the higher temp is fine because there are no hot spots–sorta like air cooling, which works fine and proves that the engine itself can handle it, not to mention higher thermodynamic efficiency with higher temps.

I still like to keep it cool–not ready for newfangled ideas.

My LT1 enjoys that concept. Reverse flow. Happy at 90 C. Flow “guaranteed” by a water pump that is gear driven and does not rely on a belt.

OTH, I was watching You tube. Old cars and stuff. One involved and ancient and almost derelict Kenworth over the road tractor. A gsant, sleeper, long wheel base, et. Powered by a “low flow” Cummins in line 6. Hoses to and from the radiator mush smaller than those usually seen. well, that old beast even cranked up and sounded OK. Mmiles in multiple 100’s…So, seemingly worked. But, the low flows are gone…

Decades ago, We went to a race. We got to look in the pits afterwards at the racers. CRA event. 60’s. Sprint cars replacing the roadsters. Most any engine allowed!! One made me curious. Powered by a 292 Ford Y block in stock condition. Coolant hoses much smaller !!! Just a bit larger than heater. Faster than most of the SBC powered cars !!! But the race main event winner was a Chevrolet, Inline 6. “The Henry and James Special”. Same smaller hoses???

No engine fans of course…