Ram 2500 Cummins Oil Capacity Guide: By Year and Engine Generation

The Quick Answer: 12 Quarts for the Cummins

If you own a Ram 2500 with the 6.7L Cummins, plan on 12 quarts of oil, or about 11.4 liters, every time you change the oil and filter. That figure has held steady since the 6.7L arrived in the 2007.5 model year, and it carries through the 2019 redesign and the 2025 High Output engine. The 2019 Ram 2500 oil capacity question comes up often because a few websites list 10 quarts for newer trucks. Ram’s lubrication data for the 2019 Heavy Duty lists 12 quarts, and so does the 2025 specification.

Gas trucks are a different story. The 6.4L HEMI V8 used in most gas Ram 2500s since 2014 takes about 7 quarts with a filter, a little more than half what the diesel needs. If you are still choosing between the two, our Cummins vs. 6.4L HEMI comparison covers the ownership costs side by side.

Ram 2500 Oil Capacity by Year and Engine Generation

The table below covers the engines offered in the Dodge Ram 2500 over the last two decades. Use it alongside your owner’s manual, which remains the final word for your specific truck.

Capacities include a new oil filter. Add oil gradually and confirm the level on the dipstick rather than pouring in the full amount at once.

Choosing the Right Oil for Your Cummins

Getting the quantity right is only half the job. The oil spec changed with the 2019 redesign, and using the wrong grade is a common mistake on trucks that have changed hands. Cummins trucks built through 2018 were specified for 15W-40 diesel oil. For 2019 and newer trucks, Ram calls for 10W-30 oil that meets its MS-10902 material standard and the API CK-4 category, with products meeting Cummins CES 20081 also approved.

Cold-Weather Oil Recommendations

Cold weather changes the recommendation. When temperatures fall below 0°F, Ram specifies a 5W-40 synthetic that meets the same standards, which helps the engine crank and circulate oil faster on a frigid morning. Most South Jersey winters do not stay that cold for long, but owners who park outside or travel north for work should keep it in mind.

Unsure about synthetic versus conventional? Our article on the advantages of synthetic oil explains the tradeoffs in plain terms.

How to Refill and Check the Level Correctly

Whether you change your own oil or just top it off, a few habits prevent the two most common problems, overfilling and running low on a long trip:

Our Dodge and Ram maintenance schedule guide lists the other service items that typically line up with an oil change, such as fuel filters, air filters, and tire rotations.

How Often Should You Change the Oil?

Ram heavy-duty trucks use an oil change indicator that tracks engine operating conditions rather than mileage alone. Towing near your truck’s rated towing capacity, long idling, short trips, and dusty work sites all shorten the interval, which is why two identical trucks can come due at very different mileages. Follow the indicator, and if your truck works hard, use the severe-service schedule in your owner’s manual.

Keep receipts or a log of every oil change. On a diesel, a clean service history is one of the strongest selling points at trade-in time and one of the first things buyers check when shopping used Ram 2500 trucks.

Other Fluid Capacities Worth Knowing

Coolant Capacity

Oil gets most of the attention, but a heavy-duty truck depends on several other fluids. On the 2025 Ram 2500, the Cummins cooling system holds about 23.8 quarts of coolant, compared with about 16.6 quarts for the 6.4L HEMI. That gap reflects how much more heat a diesel has to shed when it pulls a heavy trailer for hours at a time.

DEF and Fuel Filters

Diesel owners also need to watch diesel exhaust fluid, the urea solution the emissions system uses to clean up exhaust. The truck shows a range estimate and warns you well before the tank runs low, but towing uses DEF faster, just as it uses more fuel. Fuel filters matter too, since clean fuel protects the high-pressure injection system. Your owner’s manual lists intervals for each item, and our service advisors can check all of them in a single visit.

Expert Insight: Don’t Chase the Dipstick on a Hot Engine

Diesel Oil Service in Woodbury, NJ

If you would rather leave the 12 quarts to someone else, the service department at Performance Dodge RAM uses the correct Mopar-approved oil and filter for your engine and model year. You can book online with our service scheduler, check current Mopar service coupons, or order parts if you prefer to do the work in your own driveway.

Thinking about a newer truck? The 2025 Ram 2500 Cummins specs page covers oil capacity, coolant capacity, and the full engine details of the High Output Cummins, and our new Ram 2500 inventory shows what is on the lot right now.

Bringing It All Together

For nearly every owner, the answer is simple. A Ram 2500 with the 6.7L Cummins takes 12 quarts with a new filter, regardless of model year. What changes from year to year is the oil grade, so match the spec to your truck, add oil gradually, and check the level on flat ground.

For the complete engine picture, including fluid capacities for the latest truck, visit our Ram 2500 Cummins oil capacity and engine specs section.

Need an Oil Change on Your Cummins?

Schedule diesel service at Performance Dodge RAM in Woodbury, NJ, or stop by to see the 2025 Ram 2500 Cummins and its full spec sheet in person.

Frequently Asked Questions