I’ve taken my RAM truck for numerous drives in harsh weather conditions, but one of the major challenges is maintaining its Cummins Diesel engine.
Especially during extreme temperatures, the engine was affected by problems, such as reduced mileage, slower starts, and corrosion in the internal parts. Needless to say, I had a tough time handling various issues and even had to take my car for frequent servicing sessions.
It was then that my husband suggested checking the coolant I was using for the engine. After some thorough research and examination, I realized that the problem indeed lay with the quality of the coolant.
Since then, I’ve been much more careful with every coolant I’ve tried for the engine, and as expected, the car is performing just as desired. Hi! I’m Stacy, and today I’ve curated this extensive guide on the best antifreeze for Cummins Diesel.
Without further ado, let’s get going!
5 Best Antifreeze For Cummins Diesel
1. Zerex Concentrate Antifreeze
To begin with, I’d like to talk about this premium antifreeze that has never disappointed me in terms of quality, thanks to its phosphate-free formula. It has been a constant in my garage since I came to know about it from a friend.
Product Highlights
Automakers throughout the country have approved that this Zerex antifreeze is compatible with all diesel engines. At the core of this antifreeze is a virgin ethylene glycol concentrate of the highest standards that provides superior boil-over and freeze protection to the engine.
Plus, it uses an advanced Hybrid Organic Acid Technology (HOAT) that’s designed using a combination of organic acid-based and conventional chemistry. Such a formulation works to guard diesel engines against corrosion and rust throughout. It also possesses low pH, is phosphate-free, and has a lower concentration of silicates that adds to its anti-corrosive properties.
Another advantage is the rich nitrite content of this coolant. Rest assured you won’t encounter issues, such as liner pitting or cavitation irrespective of how long you’re driving or the driving style.
It even comes with an efficient defoamer system that’s unlikely to harm plastics, original vehicle finishes, or hoses.
What's There To Like About It?
I felt the best part about this antifreeze was how it protected my RAM truck against hard water deposits, thanks to the high-quality deposit control additives. Deposits were once a common aftermath of most of my long trips during weekends, and the result was an extensive cleaning session that took almost an entire day!
But, in this coolant, hard water deposits are a thing of the past, as is rusting due to its organic-acid based formula. So, I don’t have to rush to clean the car after each trip.
What's There Not To Like About It?
If you choose this option, packaging is the only part you need to be wary of. For two of my orders, the package arrived crumpled and torn in a few places, and surprisingly, the bottles were leaking too. This meant I had to manage with a slightly lesser amount of antifreeze on both occasions unlike other products.
Pros and Cons of Zerex Concentrate Antifreeze
Pros
Cons
- Unsurpassed freeze protection and anti-boil performance outperforms industry standards
- Hybrid organic acid technology fights rust, scale & corrosion while protecting all cooling system metals (including aluminum)
- High-quality additives protect against leaks and won’t harm gaskets, hoses, plastics or original vehicle finish
2. Mopar Antifreeze
Next up, I’ve picked another dependable option from Mopar that facilitates optimal engine performance while keeping it cool through its Organic Acid Technology. Having used this one for several years at a stretch, I can vouch that it’s pretty consistent.
Product Highlights
This coolant comes diluted with 50% water and is designed to offer year-round protection from overheating for most diesel engines.
Notably, its formulation includes a powerful mono-ethylene glycol concentrate that’s created using special organic inhibitors derived from Organic Acid Technology (OAT). This makes it perfect for providing superior anti-boil and antifreeze protection to modern vehicles, such as my RAM Truck.
Its pre-diluted composition also rules out the need to add water compared to the average antifreeze products on the market. Another point worth noting is its efficient ability to provide long-lasting protection from corrosion and rust. Thus, the cooling system metals in the engine are unlikely to suffer any damage.
But an area where this product loses out to the Zerex Concentrate Antifreeze is the protection against hard water deposits. As it lacks the deposit control additives present in the latter, it may not provide the desired protection from such deposits in the long term.
What's There To Like About It?
The reason why I feel this product stands out from many others is its ability to provide consistent antifreeze and anti-boil protection for 150,000 miles. It is formulated to provide long-lasting protection with its mono-ethylene glycol concentrate.
This ensured that I could use it for six years at a stretch before I thought of trying out a different product. In short, I was elated that my engine performed quite smoothly, as the product came pre-diluted with 50% water.
What's There Not To Like About It?
A drawback of this antifreeze is that it doesn’t come in a colored form. In the event that your car requires any servicing, technicians might have a tough time detecting whether it’s merely water or has some coolant mixed. Apart from that, I don’t have any complaints with the product as it does an efficient job of handling temperature variations.
Pros and Cons of Mopar Antifreeze
Pros
Cons
- Item Name: MOPAR Antifreeze/Coolant 50/50 Prediluted MS.90032
- Part Number: 68163849AB
- Brand: MOPAR
3. FleetGuard ES Compleat Antifreeze
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Fleetguard is known to produce some of the best antifreeze products suited for heavy-duty applications. And true enough, this one worked wonderfully to keep my RAM Truck engine in good shape throughout the chilly weather with its dual borate content.
Product Highlights
This extended life coolant containing ethylene glycol can provide complete protection to engines in temperatures as cold as -26°F in a 50% diluted form. Moreover, you can use a 60/40 premix, in which case the antifreeze protection can extend up to -60°F.
But that’s not all; this superior-quality compound has proprietary scale inhibitors, improving the cooling system of Cummins Diesel engines and extending the life of the water pump. Another significant aspect of this product is its dual borate content, which further enhances engine protection in exceptionally high and low temperatures.
The coolant is also compatible with all non-metallic parts of an engine, including elastomers and gaskets. However, I noticed that this one showed slight signs of deterioration after two years of regular use. That’s why it doesn’t score as high as the Mopar Antifreeze with regard to long-term protection.
What's There To Like About It?
I was thoroughly impressed with how this antifreeze protected my RAM Truck engine from any possible corrosion throughout. Its phosphate-free formulation and the use of a few advanced additives helped guard all the engine parts most efficiently, including those made of brass, cast iron, and aluminum.
Not only that, but I found this product quite useful for preventing liner pitting that the average options couldn’t stop. You’ll be pleased to know that the engine life extends upto 1,000,000 miles with this antifreeze.
What's There Not To Like About It?
Packaging was an issue with this coolant as well, as the seal was open for one of my orders. And to my disappointment, the product turned out to be less effective as well. This was probably because the product was contaminated during transit due to inefficient delivery. However, I didn’t notice this fault for my other orders.
Pros and Cons of FleetGuard ES Compleat Antifreeze
Pros
Cons
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4. ISO-HEET Premium Antifreeze Water Remover
I‘ve been using this premium water remover from Gold Eagle since last year, and to my relief, the truck has performed considerably well to date. Coming in a 12-oz bottle, it’s equipped with everything you would want in a good-quality antifreeze, such as enhanced absorption.
Product Highlights
Like my other recommendations, this coolant contains significant amounts of ethylene glycol, which forms the core of its anti-boil and antifreeze protection. Note that it’s made in compliance with strict specifications set by the engineers and scientists collaborating with the brand.
The uniqueness of this product lies in its different working mechanism, improving gas mileage, idling, and engine performance compared to other standard coolants on the market. This is because it is formulated to absorb five times more water from the fuel system of all Cummins Diesel engines.
You can be pretty sure that it will take out all the water dissolved in the fuel, thereby enhancing antifreeze protection. Even its ability to prevent corrosion and rust is at par with standard coolants.
But I felt the cleaning ability of this product could be improved. After all, it couldn’t clear hard water deposits on some parts of the engine as efficiently as the Zerex Concentrate Antifreeze.
What's There To Like About It?
What I liked the most about this coolant was its excellent ability to prevent cold starts even in the lowest of temperatures. On those mornings when I had to leave home early for work, the chilly weather couldn’t prevent me from starting my RAM truck quickly.
Additionally, it helped prevent stalling of the vehicle in the middle of my journeys through its smooth idling, something I’ve often faced with ordinary antifreeze products.
What's There Not To Like About It?
I wished this product came in a bigger bottle as that would’ve been more economical. Since it’s available in bottles of 12 oz, it can get costly if you purchase in bulk. I once used it throughout all seasons and indeed had to spend much more compared to other high-performing products.
Pros and Cons of ISO-HEET Premium Antifreeze Water Remover
Pros
Cons
- PREMIUM WATER REMOVAL: Absorbs 5 times more water than regular gas-line antifreeze, providing superior fuel system protection and performance.
- YEAR-ROUND PROTECTION: Prevents fuel-line freeze-up in winter while removing water from fuel system throughout all seasons to maintain optimal engine performance.
- UNIVERSAL COMPATIBILITY: Safe for use in all 4-cycle and 2-cycle gasoline engines as well as diesel engines, making it versatile for various vehicles and equipment.
5. ACDelco DEX-COOL Antifreeze
Lastly, I’ll be reviewing this antifreeze from ACDelco that has a much longer shelf life and is especially designed to go long intervals without servicing due to its chemical composition. To know more about this product, read the next few sections.
Product Highlights
This premium-grade antifreeze utilizes carboxylate technology to provide the desired temperature protection to Cummins Diesel engines. You should also note that such a chemical formulation reduces the breakdown of metallic components coming in contact with the fluid.
It can even provide long-lasting protection to heavy-duty engine parts made of materials, such as steel, solder, copper, and cast iron. That’s why you can rule out chances of rust or corrosion in the long term.
Another advantage of going for this product is that it comes in a distinct orange hue, unlike many other coolants out there. So, technicians won’t find it tough to detect the fluid during servicing.
But I was a bit disappointed to notice that this coolant was, at times, unable to provide a quick start in very low temperatures. This is one area where it loses out to the ISO-HEET Premium Antifreeze Water Remover.
What's There To Like About It?
Thanks to the efficient non-silicate formula of this high-quality coolant, the water pump performance improved considerably. I had no problem maintaining the efficiency of the water pump and there was no significant overheating of the engine either.
It circulates consistently through the pump, ensuring that it’s active in all weather conditions. Thus, with no overheating issues, combined with the long life of the other engine components, I can take the car out on a hot Texas morning without any hassle.
What's There Not To Like About It?
The only problem I faced for one of my orders of this antifreeze is that the bottle was leaking and a large part of the liquid was smeared within the box. As such, I had to order another bottle to make sure I had enough for the engine. That’s why I’d strongly suggest checking the contents of the bottle right after delivery.
Pros and Cons of ACDelco DEX-COOL Antifreeze
Pros
Cons
- ACDelco 10-101 DEX COOL (ORANGE)
- Contains A Bittering Agent
- OEM
Buyers Guide
Getting the best antifreeze for Cummins Diesel might seem slightly easier when you know about the best products out there. But you will still need to be aware of some key factors that determine their performance in the long run. That’s why I’ve compiled this section to help you make a well-informed decision:
1. Type Of Antifreeze
Know that engine coolants available out there are of various types and the type that’s suitable for your vehicle will be recommended in the manual for the engine. Notably, these come in different colors and their names vary based on their composition.
The ones formulated with Inorganic Additive Technology (IAT) are available in green hues. On the other hand, the orange-colored coolants utilize Organic Acid Technology (OAT) or Hybrid Organic Acid Technology (HOAT).
Remember that a Cummins Diesel engine can work efficiently with both OAT and HOAT coolants provided they are of the desired quality. But a word of caution — be careful not to mix the types and colors as that might not be beneficial for the engine.
2. Corrosion Inhibitors
Checking the anti-corrosive properties of the coolant is also of prime importance. After all, preventing corrosion of the metal parts is key to ensuring the smooth performance of an engine.
Most coolants come with a range of corrosion inhibitors that are formulated differently for different regions as per the climate and weather. But you should note compounds like phosphates and silicates that are claimed to be anti-corrosive might have opposite effects on the engine.
That’s why products with gentler agents, such as carboxylates are ideal for preventing corrosion. To ensure that you’re going for a suitable option, it will be best to check some customer reviews that talk about the anti-corrosive properties of the coolant.
Note that the product should provide adequate protection to all metallic engine parts, such as those made of copper, aluminum, steel, solder, and cast iron.
3. Water Content
Another vital point to consider is whether the antifreeze is diluted with water or is available in concentrate form. Those coming in pre-diluted forms are comparatively easier to use as you don’t need to add water separately to them.
However, some coolants are meant for use in the undiluted form itself and you should be careful to check the concentration of the product you’re going for. If you plan to use a concentrated coolant, first make sure whether it’s suitable for the Cummins Diesel engine of your vehicle.
4. Anti-Gel Formula
In case the temperature in your region often gets below the freezing point during winters, you should ideally use a lower temperature-rated anti-gel coolant. Notably, such antifreeze products are specially designed to retain their liquid form at cooler temperatures, preventing the water in the engine from freezing.
5. Primary Ingredient
The ingredient present in the largest proportion in a coolant determines its efficiency in providing the desired antifreeze and anti-boil protection. For instance, the use of ethylene glycol as the primary active ingredient can make all the difference in a coolant. That’s because it’s capable of protecting engine parts in low temperatures like -26°F.
On that note, checking some relevant customer reviews can be helpful for ascertaining the effectiveness of the primary ingredient.
6. Temperature Range
The optimum range of temperature for any engine is between 0 and 50°F. Additionally, some antifreeze products are specially formulated for operating in extremely cold weather and ultimately protect the engine against freezing. But there are still some others that need to be heated prior to use to ensure adequate protection from corrosion in cold weather conditions.
Frequently Asked Questions
Yes, antifreeze and coolant are the same, as they serve the same purpose — protecting the engine from boiling over, corrosion, and freezing. Apart from that, these products can help lubricate and clean engine parts, such as valves and pistons.
A crucial step to keep in mind while using an undiluted coolant is to include water in the required ratio. Note that the user manual of the engine will mention the ratio and type of water you’re allowed to mix.
You must be careful in this regard as a coolant that’s too weak or too strong might damage the engine. This will also depend on the formulation and the climate of the region in consideration. However, a range of 40:60 or 60:40 is generally specified to facilitate efficient corrosion protection.
Typically, there is an approximate time period mentioned on the container of the coolant.
But there are some signs that indicate you should replace the coolant immediately. These include a higher temperature shown on the gauge reader while the engine is operating, a grinding noise from the car hood, and a leaking antifreeze.
My Final Recommendation
On that note, I’ve almost reached the end of my guide, and I hope you’ll now find it easier to choose a suitable antifreeze for your Cummins Diesel engine.Â
Don’t delay protecting your engine against harsh temperatures to derive the best performance out of it. But before I call it a day, I’d like to quickly take you through my favorites from the list.Â
The Zerex Concentrate Antifreeze is my stand out option, as it provides all-round protection to any Cummins Diesel engine. What does the trick is its high-quality ethylene glycol content and the use of advanced HOAT technology.Â
However, if you need coolant that offers more long-lasting engine protection, I’d suggest going for the Mopar Antifreeze. With that, it’s time for me to say goodbye and I’ll see you soon with another informative guide!Â