RMI-25 Cooling System Treatment
RMI-25 Cooling System Treatment is a very low-cost, extremely effective defense against cooling system failure in all engines. It is a total pour in/drive-away system which removes rust, scale and corrosion, prolongs component life, increases water filter longevity, and has no disposal costs when used with water only.
- Cleans radiators, engine blocks, heater cores, hoses
- Inhibits rust, mineral deposits, erosion, pitting
- Lubricates water pump seals, heater control valves, thermostats
- Conditions coolant for better heat transfer
- Stabilizes pH for correct acid-alkaline balance
- Flushes & cleans entire cooling system while the engine operates
- Detects leaks with fluorescent dye
8 fl oz treats 5 gallons (19 liters)
Significantly reduce water pump, radiator and cooling system failures! There is no downtime, just pour it in and drive away!
RMI-25 is compatible with all types of antifreeze/coolants¹, including high-and low-silicate types of antifreeze, as well as propylene glycol and ethylene glycol. It can be used in all types of radiators and is safe for all metal and aluminum engines. Greatly increase the life of all your engine’s cooling system components and reduce overall maintenance costs!
RMI-25 Cooling System Treatment
Engine cooling systems rely on cleanliness

RMI-25 cleans, conditions and protects the cooling system as the engine operates.
An engine’s cooling systems is often easily neglected – until it becomes a costly problem. A properly maintained cooling system is designed to provide optimal service for many years. The cooling system does not mean just the radiator and antifreeze/coolant, but it consists of numerous components, including the water pump, hoses, cooling fan, heater core and valves, thermostat, engine block, and head(s).
Standard antifreeze/coolant cannot offer full protection

RMI-25 works for all cars, trucks, agricultural, off-road vehicles and machines
Not surprisingly, cooling system efficiency relies on cleanliness. Unfortunately, antifreeze/coolant has no cleaning effect, and the minimal rust and corrosion inhibitor package in antifreeze/coolant deteriorates over time whether the engine is operated or not. However, the protection from freezing and additional ‘boil-over’ protection remains the same even when the inhibitor package has completely degraded. Often, tap water (which usually contains minerals) is used with antifreeze/coolant. This is a huge No-No, as these minerals accelerate the breakdown of the inhibitor package, allowing the formation of rust, scale, and consequential corrosion, which damages key components of the entire cooling system components, causing premature failure.
Worryingly, a standard check of antifreeze/coolant for freeze or boil-over protection will reveal nothing about the rust, scale, corrosion, lubrication factor, electrolysis, cavitation, erosion, and pitting that is going on undetected in the cooling system.
RMI-25 is the complete cooling system treatment
A truly unique product, RMI-25 Cooling System Treatment provides a completely safe and thorough cleaning process of the entire cooling system whether it is needed or not, and then it protects after it has cleaned the metal surfaces. Rust, scale, and corrosion cannot steadily accumulate like it can with the typical sodium nitrate borate type inhibitors. Even Long-Life coolants are not adequate deterrents to the formation of corrosion and mineral deposits.
RMI-25 is the low cost way to extend the life of your engine

RMI-25 is non-hazardous, non-toxic, and completely biodegradable.
RMI-25 Cooling System Treatment cleans, protects, lubricates, inhibits, and prevents cavitation and electrolysis. It also has a superior “water-wetter” additive which makes water a more effective ‘heat-dispersing’ coolant. Combine all those, and then include an oxygen scavenger, and even a black light leak detector, for an efficient formula to “keep it cool” and make the cooling system last much longer at a surprisingly low cost.
As it contains no Silicates, Nitrates, Borates or Molybdenites in the formula, RMI-25 Cooling System Treatment has no detrimental effect when added to anti-freeze, whether it is the old “green stuff” or the Long-Life Coolants, including propylene glycol or ethylene glycol. It contains no dangerous chemicals, and, in its original state, it is non-hazardous, non-toxic, and completely biodegradable. In certain applications where freezing is not a concern, using RMI-25 with distilled-water only is all that is needed; thus, the high cost of antifreeze in such situations can be eliminated. To avoid system damage, antifreeze must be added to the cooling system where possible freezing temperatures are likely to be encountered.
Test cooling system pH level every 15,000 miles (24,000 Km) or 300 hours, and if necessary, re-treat the cooling system with RMI-25. Correct pH is 8.2 – 10. Simply use pH Test Strips to test.
¹When used with waterless, alcohol-based coolant, the overall benefits of RMI-25 and the coolant may be reduced.
STORE ABOVE FREEZING 32°F (0°C)
Fast shipping*: between 2-3 business days across the Lower 48 States using FedEx Express.
Free shipping* to the Lower 48 States for all orders over $50 (before tax). Discount shipping everywhere else.
$10 shipping fee added in Checkout to all orders below $50 (before tax).^
Be astute – add it to any other additive product to get Free Shipping!^
^Lower 48 States only.
*Applies to retail quantities only. For commercial quantities, please contact us for further details.




RMI-25 saved a core
“RMI-25 really is a great product! Saved me from doing a core!”
Ben B, Westfield, MA
Great service!
“Thank you! Thanks for all your help and information along the way. And I really appreciate you getting my order shipped so quickly. I just received a notice from Fed Ex that the package is out for delivery today – that’s some world class service! (Ordered Friday night, shipped Saturday, out for delivery Monday)”
Brian F, Austin, TX
Performs exceptionally well
“Received the RMI-25 Cooling System Treatment very quickly! Product performs exceptionally well. Using in a stand alone 300 Hp Cummins engine for farm irrigation. Core of radiator is visibly cleaner after 20 hours of use. Great product! Thanks.”
Ray F, Dover, FL
It works
Jack C, Saint Helens, OR
Great product!
“I got the RMI-25 16 ounce. Fast delivery and great product! Thank you.”
Mike P, Tulare, CA
Couldn’t believe it
“The RMI-25 worked great, couldn’t believe how quickly it cleaned the reservoir. Going to flush and re-add in two weeks, seems very promising. Don’t like off the shelf products, spent a good hour or two finding the best all around coolant additive and cleaner, that’s how I found you guys and RMI-25. Thank you for taking the time to legitimately respond to my questions. It was extremely helpful. I will definitely be keeping in touch, passing the info along, and ordering the other products you also recommended.”
Jake V, Green Bay, WI
Great customer care
“Thanks you so much for getting my order for the Ultimate Gasoline Pack straightened out. Great customer care!”
Andrew T, Davison, MI
RMI-25 worked perfectly
“Thank You! The RMI-25 worked perfectly.“
Keith S, Coplay, PA
Quick shipping!
“Thanks guys, my package arrived safely. QUICK shipping! I’ll get some more soon!” (RMI-25 Cooling System Treatment)
Russ S, Seaford, NY
A great product RMI-25
“Shipped super quickly! I’ve used RMI-25 before, its a great product.”
Mark S, Merritt Island, FL
Fastest shipping ever!
“Fastest shipping I have ever gotten. Next day delivery from Utah to Wisconsin. Incredible!” (RMI-25 Cooling System Treatment)
Mark S, Oak Creek, WI
Great product!
“RMI-25 Cooling System Treatment – a great product at a great price!”
Mike B, Petaluma, CA
This is great stuff!
“This is great stuff for your cooling system! Arrived quickly at a reasonable price.” (RMI-25 Cooling System Treatment)
Mark B, O Fallon, IL
Some quick shipping!
Man, that was some QUICK SHIPPING!! Thank you! (RMI-25 Cooling System Treatment)
Jack J. Lakelands, FL
AAA+++
“Thanks for the FAST shipping! AAAAAA+++++++” (RMI Cooling System Treatment)
Fred S, Margate, FL
Great service!
“I received my order yesterday without any issues. Thanks a lot for sorting this out for me, great service!“
Moritz K, Germany
Save money!
“Great product and fast shipping. Buy larger size saves you money.“
Brad J, Wildomar, CA
Y’all Rock!
“Thank you so much, appreciate your communication and customer service, y’all rock!” (RMI-25 Cooling System Treatment)
David S, Long Beach, CA
Have used it for decades
RMI-25 is a great product!!! I’ve used it for decades. Delivery was fast. I’ll buy it again and again!!!
John W, Washington, UT
Ram heater core fixed with RMI-25
“I was doubting anything would help but it did! I put in 16oz of RMI-25 and have about 20 hours of driving so far. The heat in my 2018 Ram 2500 went from barely warm, maybe 110F max to it now gets warm enough, at least 140F, to drive comfortably in 20F degree weather. My windshield melts again! Seems to keep getting hotter. The cost is nothing compared to a heater core replacement. I am very happy I tried it and plan on telling anyone I come across with the same issue. Incredibly fast shipping too! Thank you very much!“
James B, Erie, PA