Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

engine coolant additives, redline water wetter etc.

engine coolant additives, redline water wetter etc.

engine coolant additives, redline water wetter etc.

Has anyone actually tested any engine coolant addatives out? did you notice any difference in temp from the 10$ bottle? the redline water wetter supposedly makes your coolant transfer more heat etc, but what im wondering is does it actually work, and if so how. they have charts showing a test proving (allegedly) that the product improves heat transfer, but being a skeptic Im looking for some experiences from anyone out there.



RE: engine coolant additives, redline water wetter etc.

I've never used it, but it's supposed to work by breaking the surface tension of the water.  I've heard of people added a drop or two of dish washing soap to do the same thing.  Not sure how successful this would be though.

RE: engine coolant additives, redline water wetter etc.

Any surfactant will reduce the surface tension (by definition). All soaps and detergents are surfactants. That's partly how they work, by reducing surface tension and allowing the water to work into the surface and wet things.

Foam is the main problem, as it will insulate the surface.

Some surfactants foam much more than others.

It's been nearly 30 years since I worked with surfactants, so I am a bit rusty on the details.

Ethylene glycol lowers the surface tension of water, and reduces freezing temperature, and raises the boiling point. That is why, as far as I know, it is the basis of all leading brand coolants.

It will not make your engine run cooler, in fact, under identical conditions, it will raise the coolant temperature (as it has a lower specific heat than water), thereby increasing the thermal efficiency of your engine.

If the temperature output of your engine increases, the glycol will withstand higher temperatures without boiling. This greater temperature difference between the coolant and the air flowing through the radiator, will improve the cooling efficiency of the engine, to a greater degree that the lower specific heat will reduce it.

Bottom line. Glycol will increase your indicated temperature, but won't boil over so easily. It will marginally increase your engines thermal efficency.

If taken into consideration at design stage, it will allow the designers to slightly decrease air intake to the radiator, thereby improveing the cars aerodynamics.

It also helps lubricate the water pump

Dissadvantages. Depending on rubber formulations, It tends to rot hoses if used in high concentrations. The higher water temps can also degrade hoses quicker.

The higher underbonnet temps can degrade other components, including batteries and PVC electrical wire insulation.


RE: engine coolant additives, redline water wetter etc.

As with most miracle in a bottle products, the consumer is expected to believe the marketer's test results.  And considering the low levels and types of active ingredients in these products, the manufacturers obviously have a strong profit motive.  I did some rig testing of some of these products a couple years ago and didn't see any discrimination.

The wetting explanation of how it 'works' is intriguing, but one could just as legitimately argue that laying down a monolayer of surfactant at the radiator/water interface would be as likely to decrease heat transfer by insulation instead of increasing it by thermal coupling.

A different but very reliable way to reduce coolant temperature is to switch to a lower temperature thermostat.  Why does one want to lower the coolant temperature unless boilover is a problem?  Nevertheless, the market seems to have accepted these products, so they must serve some purpose.

RE: engine coolant additives, redline water wetter etc.

This stuff is starting to sound like slick 50, I think there isnt enough teflon in my bearings. i agree about swithing to a lower temp thermostat, i guess if the problem was bad enough just a restrictor could be used in it s place. thanks for the input.

RE: engine coolant additives, redline water wetter etc.

Dr. Webb writes:

A different but very reliable way to reduce coolant
temperature is to switch to a lower temperature thermostat.
Why does one want to lower the coolant temperature unless
boil over is a problem?  Nevertheless, the market seems to
have accepted these products, so they must serve some

In a properly designed engine, you don't want to reduce
the coolant temperature at all.  That's the trick.  The
most thermodynamically efficient coolant temperature is
as hot as possible before things break, boil over, or the
engine detonates.

Engines are heat pumps. (very wasteful at that)  The
more heat you transfer to the coolant and dump out the
radiator, the less heat is available to expand gas and
create power at the flywheel.

Finding the best coolant and the best coolant temperature
without creating hot spots, (localized boiling) without
causing excessive differential heat expansion (due to
different coefficients of thermal expansion of various
metals and various operating temperatures) and still allow
enough reserve cooling for the constantly variable power
settings is truly the "art of engineering!"

If a bottle of miracle potion was the cure all,
vehicles would come like that from the factory.  The
folks who design engines and cooling systems have
been doing it for a while.  I doubt they spend a lot
of time at the Rxx Lxxx site nor does the Rxx Lxxx
salesman have Ford, GM, or VW, etc. on their call list.


RE: engine coolant additives, redline water wetter etc.

Onya (Aussi for very good) Chumley.

Spot on. Thats why manufacturers spend money to install a thermostat. They design a cooling system to cope with maximum heat output in the hottest conditions they expect the car to operate in, then use the thermostat to maintain the OPTIMUM temperature under less demanding conditions.

As far as I know all auto manufacturers use about 30% ethylene glycol in water with some proprietory mix of corrosion inhibitors.

If snake oil or other miracle remedies worked, they would use it, then reduce their costs by reduceing radiator size.
They could also make grill openings smaller and pick up a little in fuel economy.

That is, unless you believe in conspiracy theories, or that the thousands of professional engineers who work together to design the worlds auto's are all incompetent morons.


RE: engine coolant additives, redline water wetter etc.

You can probably put this into the catagory of snake oil/eye candy products. I had a good friend that was a manager of a local auto parts store until they were bought out by a big chain, and he used to provide me products like these to test in my E.T. bracket drag race car. The idea was that if they worked, they would continue to supply me with a reasonable amount of these products, in return, they would use my name to try to sell these products. I am a second generation drag racer in this area, and my name is fairly well known here, and my reputation is good.

Anyhow, one of the products supplied to me was the Water Wetter. I have been bracket racing the identical engine/transmission combination for 13 years now, and I know how the car acts inside and out. I start my water burnout at 145 degrees F, come out of the water hard right to the starting line, and stage at 185 degrees F. Usually by the end of the run, I am at about 195 degrees F, and by the time I get up the return road, and to my trailer the temperature is about 205 to 208 degrees F. This is using straight water, if I mix 15% ethylene glycol, which I do at the beginning of the season when there is still a possibility of temperatures at night going below freezing, these numbers increase by about 5 degrees F, unless the air temperature is very cold that day. With the water wetter mixed with my straight water, there were no differences in these standard, long proven numbers. I'm glad the auto parts store supplied my with that bottle, and I didn't have to pay 10 bucks for it.

They also supplied me with a set of Split Fire spark plugs one time (no difference), and an oil change with Royal Purple oil ( no change there either), and the venerable Slick 50 (worthless).

Since the big chain that bought the store out is into the eye candy products for ricer cars, I'm going to see if they will donate to me a set of those 5 inch exhaust tips to put on the end of my headers. You know, the ones that have the ring of fire around them (red LEDs). That should give me at least 10 horsepower somewhere, shouldn't they? LOL.

'85 Mercury Capri
Mild 351 Cleveland powered
6.78 @98 mph 1/8 mile. 1.45 60 ft.

RE: engine coolant additives, redline water wetter etc.

thanks for the info guys. i appreciate it. save your money for real equipment.

RE: engine coolant additives, redline water wetter etc.

Not to beat a dead horse but...
   One example that kinda proves the point is an opposite situation: A product lives up to its claims and the OEMs (gasp!) use it! Mobil 1 full synthetic, when it first came out, promised a whole bunch of stuff, some of which people thought were just marketing claims, but more and more OEMs are now swallowing the cost (altough something tells me they aren't paying $4.50 a quart) to put it in their performance cars to keep things together.

RE: engine coolant additives, redline water wetter etc.

I think you have to read their page very carefully. I met the Rep. at a show many years ago, and at least then, they did not recommend its use with any type of antifreeze, what I was told was it really didnt help the wetting characteristics enough to warrant its use. Indeed, based upon a reduction of only 8 degrees in a stabilized temp engine, very few of us could justify its cost. Where it would shine though is in a circle track race engine, where stabilized temperatures dropped 18 degrees. Another possibility, though more for the drag guys would it not also reduce the cool down period between rounds?
Just thoughts, what I will agree on is it has no real advantage for a street driven ( with antifreeze )car.

RE: engine coolant additives, redline water wetter etc.

On thinking about this, I cannot see how it changes the water temperature, maybe the metal temperature in the combustion chamber, though I doubt it, but not the water.

If it improves heat transfer from coolant to metal, surely it will improve the heat transfer into the radiator core just as effictivly as it transfers the heat out of the combustion chamber, resulting in a similar water temp for a cooler head, and hotter air under the bonnet.

I would have seen this as a bouble whammy dissadvantge to both power and fuel efficiency, as more heat is lost from work to atmosphere, and higher underbonnet temps might reduce air density in the inlet tract and reduce power.


RE: engine coolant additives, redline water wetter etc.

Again from the practical side---I have used Red Line Water Wetter and water soluable oil as a corrosion inhibitor in the cooling systems of my Model A and my race cars for years.  I choose to use the Red Line stuff in the race cars simply because it is less messy than the oil.  I cannot use EG or PG based coolants because of the rules in most racing organizations (SCCA, VARA and HSR/West for me).  The use of EG coolants in the non pressure Model A results in overheating and using the PG based coolants yields higher coolant temp than I am comfortable with (~300f).


RE: engine coolant additives, redline water wetter etc.


If it stops corrosion, lubricates the water pump, you don't need antifreeze and can't run glycol, it sounds like just thr right horse for your course.

I still doubt the advantages of wetter water.

We just run plain old tap water in the 1913 model Little Giant, as it has a large water capicity and boils gently on long steep hills. We top it up well before it boils dry. The latent heat of vaporisation crudely makes up for a lack of radiator and airflow capicity. Yes, she has no cooling fan and no water pump.


RE: engine coolant additives, redline water wetter etc.

Good Morning to all-
My shop prepares F-bodies (Firebird and Camaro) for various levels of motorsports (Speed World Challenge GT, SCCA A-Sedan, SCCA SSB (yes a v-6!).  Both the L-98 base of the A Sedan and the World GT LT-1 reverse flow cooling system can see some extremes in cooling system temperatures especially in the mid-atlantic area from July thru September.  We've tried every conventional solution and have it manageable for now, but as the prep shop I'd like more cushion.  Evans Cooling has some interesting technical data @ Evanscooling.com.  It looks like part of the solution but I'm interested if any one has looked into it, used it, etc.  Sorry about the late post.
CRG Performance

RE: engine coolant additives, redline water wetter etc.

Here's a thought - since breaking surface tension in hot water is the key, how about the rinse additive in your dishwasher? Works for us in the race engines.

Keep the wheels on the ground

RE: engine coolant additives, redline water wetter etc.

Okay Bob---You got my attention.  After totalling the mini at Willow Springs last month, I am interested in anything that will save me money.  The Red Line stuff works but is outragiously expensive for what it does. The race organizers will not allow anything else except water soluable oil (messy) or plain water. Do you have anything to say about corrosion/rust inhibitors in the dishwasher stuff?
My figures for the Water Wetter last race test we did were 200f water temp and 195f oil temp on plain water and 190+ water and 180+ oil in one test and the next day 195 plain water/190 wetter---oil temp was about 160 to 170 both tests on Saturday (crashed in turn 1 second lap on Sunday, so no figures). Weather was clear and windy, air temp about 85/95 both days.  Not terribly scientific but it indicates to me that there is a good possibility that some improvement in overall engine temp is accomplished by using the Red Line stuff.  Like I said before, I use it for corrosion control and any benifits above and beyond that are "just gravy".


RE: engine coolant additives, redline water wetter etc.

The two areas of potential problem I can see with useing cleaning chemicals, including dishwasher rinse aid is foaming and alkalinity.

If it is inclined to foam, it will increase tendency to cavitate at the pump inlet or wherever you get high water velocity around a tight bend or sharp edge.

This cavitation might cause hot spots in the combustion chamber.

If it is slightly alkaline, and most surfactant formulations are, it will attack any aluminium parts it comes into contact with.

You certainly can use something like you propose, and that is probably all that the redline is, but you will need to check pH, and keep it just very slightly on the acid side of neutral, say pH 6.8

You can also add some silicone antifoam if necessary, and possibly a little corrosion inhibitor. When I worked in the lab at Geigy, back in196? something or other,we had a product we sold to the automotive coolant system additives industry. I think it was called Amine O. It was a corrosion inhibitor, and might now be sold by CIBA, or whatever they call themselves this year.

Another source of corrosion inhibitor might be suppliers of watertreatment chemicals to industry, for such things as cooling towers etc


RE: engine coolant additives, redline water wetter etc.

Thanks, Pat.


RE: engine coolant additives, redline water wetter etc.

Interesting thread, enjoyed reading all this.

I run a small engined road / trials / hillclimbing car (called a Liege) in UK using a modified Reliant Rialto 850 cc engine. The engine has an alloy block with cast iron wet liners and and an alloy head. It runs a high compression ratio (probably about 12.5 to 1).

The car temperature gauge climbs into the upper part of the gauge during fast cruise (well, relatively fast, it's only 850 cc) and so I had considered buying some Redline Water Wetter in an attempt to ease things. I'm glad I didn't, you guys have confirmed what I thought - a waste of money, especially as it's more like $23 in UK!

One point on the idea of using washing up liquid - I also considered that but I understand it contains (sodium) salt which is corrosive to ally and iron....

Paul W

RE: engine coolant additives, redline water wetter etc.

PEW---The "Water Wetter" works but is rather  pricey but, then again, all the Red Line products are pricey.  That changes nothing.  The stuff still works as an anti corrosive and is a LOT more convenient to use than WSO.
In an 850cc cooling system, one bottle should be good for several applications, at least 3 or 4.  That helps spread the cost.  Try ordering from the US , www.pegasusautoracing.com
or such.  It's only about 8 bucks retail over here and I get three fluid changes on my mini.  That means that one bottle is good for a years worth of racing (hopefully)!
Obviously not the perfect solution but at some point I just surrender to the "convenience factor".


RE: engine coolant additives, redline water wetter etc.

Thanks, Evelrod,

I will perhaps search some out next time I am in USA. If it's only $8 for 3 shots then it might be worth a try after all.

RE: engine coolant additives, redline water wetter etc.

Going off on a little bit of a tangent here but...

Will switching to a lower temperature thermostat actually reduce the operating temp of the engine? It was already stated earlier in this thread that hotter is better, but i see lots of people installing 180 degree t-stats in there vehicles that were designed to run 190 degree t-stats. They think that running it cooler will add more power. But i always thought that the t-stat just controlled the minimum temperature of the engine, once your really running the car hard the t-stat stays open and the temperature of your engine is determined by the efficiency of your radiator, water pump, and coolant. Am i right?


RE: engine coolant additives, redline water wetter etc.

Yes, Jon. All that plus, obviously, ambient temp and  the engine loading/power output, etc.  If the cooling cap of the system is greater than demand then a 'cooler' t stat will lower temp.  Most modern systems are sized for max output in Arizona...


RE: engine coolant additives, redline water wetter etc.

"sized for max output in Arizona... "

-If one ever notices, that's where most of the auto rags' new model spy photos are taken.

RE: engine coolant additives, redline water wetter etc.

My science project:

Just to be provoctative, I've constructed a little experiment. Try it for yourself.


Electric stovetop, heated to max temperature
Aluminum pie pan
Ethlyene Glycol AF
Water Wetter
Dishwashing soap

The first step is to put a pound of room temperature water in the pie pan and place it on the stove. Time how long it takes to boil.

Boiling condition is identified when the solution reaches a plateau temperature. Temps were observed at 15 second intervals, because I was doing this by hand. Temps in degrees F, because that was the thermometer I had handy. I did each test twice, to check my times.

Repeat with a mixture of water/water wetter, water/glycol (50%)/water wetter, water/glycol (50%), water/diswashing soap.


The stovetop represents a hot engine component, the coolant is the coolant, and the air/coolant interface is the radiator. The mass of the pie tin is small enough to be disregarded. The longer the coolant can go without boiling, the more heat it can transfer. Lots of differences between this model and a real cooling system (thanks in advance for pointing them out), but it's just a quick and dirty.


From best to worst, time is in seconds:
(time, plateau temperature, solution)

  180  212   Water/Water Wetter
  180  225   Water/Glycol/Water Wetter
  165  225   Water/Glycol
  150  212   Water/soap
  120  212   Water

Test conditions: 70F ambient, elevation 100M,stovetop temp 800F.

Water wetter seems to do what they advertise. Put a few drops in a boiling pan of water, and the vapor bubbles disappear, replaced by no bubbles or streams of tiny bubbles. Clearly, more liquid is in contact with the pan.

Diswashing soap was less effective, and foamed a bit. I think that liquid soap is partly water, which may explain it's lack of effectiveness.


It works in the pan, but can't assume it works in the car. I doubt that observed temperature would change, unless your car was very close to overheating in normal service. But hot spots would probably be reduced or eliminated. We can debate the value, but I can't seen any harm.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close