How Much Coolant Does a 5.9 Cummins Hold? (Type and Capacity)
Fluids are important. Not only are the right fluids vital to your health, but your truck’s or RV's engine also needs the right fluids to stay healthy. To be sure those engines last a long time, you should avoid over-filling the tanks. Knowing the coolant level is important if you want your engine to not over-heat.
The Cummins, 5.9 L engine takes 10 liters of coolant without the EGR. With the EGR attached, it will take 11 liters. This equals 2.6 gallons for the former capacity and 2.9 gallons for the latter. These figures are for the 6-cylinder motor only.
To learn more about this engine and its coolant capacity and type, just continue to read our article. It has the information you want to know about so you can add the right amount when it is time to change the coolant.
How Much Coolant Does a 5.9 Cummins Hold?
You will hear different capacity numbers floating around if you check the different discussion forums on this motor. But the standard capacity is as reported with some people saying as low as 2 gallons and others as high as 4.
Our information came from a data sheet that contained all the specs and capacities this engine has. You can read that data sheet at this link . We have no suspicions about the content despite its originating source.
That data sheet is also for the 6.7 L Cummins engine so you should be covered no matter which of those two engines you own. The coolant inside this engine should be changed every 50,000 to 60,000 miles. That is not hard to do either.
What Coolant Should I Use In My Cummins 5.9?
Some people have stated that you would need a special diesel coolant which can be pinkish, yellowish, or orangish in color. But that recommendation does not seem to be correct.
Our research has found that you can use the standard auto coolant that is green in color. The reason you can get away with this type is that the 5.9 L Cummins is a light-duty engine made for light truck use.
If you are unsure, you can always talk to your mechanic and see what they say. The diesel coolant runs about $12 to$14 per gallon so double-check to make sure. You may be able to run extended-life coolant in the engine but again, double-check before buying.
This is a topic that is under a lot of discussion and different people recommend a brand and type that they favor but may not use personally. Some people also change their coolant well before the recommended time frame.
For example, if they are using 100,000-mile coolant, they will change it at 50,000 miles. That is a bit much but they do not want any surprises or damage later on down the road. You get to decide when you will change your coolant and which type you will use.
5.9 Cummins Coolant Type
It has been said that Cummins recommends the Fleetguard brand of coolant and anti-freeze. The company says that this type is the most stable and effective coolant you can buy.
Plus, they say that the Fleetguard brand offers the engine the best protection possible. That is because this brand is supposed to stop the following engine ailments-- scales, corrosion, liner pitting, & voids.
Cummins also says that the yellow HOAT coolant lasts the longest and the amount you will need will depend on your type of engine. The HOAT has been recommended by others as well.
That is not a brand name but a coolant type made for diesel engines. There may be a GO-5 or a GO5 letter-number code after the HOAT name. However, you do get a choice as there are 4 different coolant types for Cummins engines on the market today.
Check with your mechanic, or auto parts store to see which of those 4 types is best for your Cummins 5.9.
Best Coolant For a 5.9 Cummins
We have run into several brand name recommendations and there is some overlap in those lists. Your cost will depend on where you buy your coolant and the brand you like to use. Here are a few of those recommended coolant brands:
1. Valvoline Zerex Heavy Duty Extended Life Coolant
It is Cummins 14603 approved that meets the ASTM D6210 specs as well.
This antifreeze is designed to prolong your engine’s lifespan. It’ll be in service for 3 yrs/ 7000 hours/ 300,000 miles. Whichever comes first.
2. Fleetguard Extended Life 50/50 Prediluted
Additionally, the Fleetguard coolant has very long service periods. Upon the initial filling, your engine will run for 150,000 miles or 4000 hours. So it saves you from the hassle of frequent refilling and a lot of expense.
3. Mopar 50/50 Prediluted Antifreeze
This coolant has an exceptionally long service life. Can last up to 10 years in a single filling. Although, if your engine reaches 150,000 miles before that, you should change the coolant earlier. ** all this section’s information is taken from https://www.carfluidsexpert.com/best-antifreeze-for-cummins-diesel/
The Major Coolant Types
1. HOAT – Hybrid Organic Acid Technology
This works for the 5.9 as well as the 6.7 Cummins engines.
2. IAT- Inorganic Acid Technology
For heavy-duty engines and does require a lot of servicing as well as supplements
3. OAT – Organic Acid Technology
Made for light and heavy-duty engines as well as gas and natural gas motors.
4. NOAT – Nitrated Organic Acid Technology
Similar to the previous type except it contains nitrate.
Some Final Words
The 5.9 L Cummins motor has been around for some time. You can keep it running by using the right coolant. If you still have your owner’s manual, check to see what it says. That will be the best source to follow when it comes to re-filling your radiator.
For most diesel vehicles that are in the light truck or SUV categories, you can get away with using the same coolant all car owners use for their gas engines.
