2026 Ram 2500 Oil Type and Capacity Guide (2010–2026)
The 2026 Ram 2500 pairs serious heavy-duty engines with serious lubrication requirements — and the right oil specification has changed more than once across the 2010–2026 model run. The 6.7L Cummins Turbo Diesel I6 holds 12 quarts and shifted viscosity recommendations starting with the 2019 redesign. The 6.4L HEMI V8 took over as the standard gas engine in 2019 (after sharing the lineup with the 5.7L HEMI from 2014–2018) and uses a 0W-40 synthetic that’s distinctly different from any Ram 1500 spec. This guide covers every Ram 2500 engine offered from 2010 through 2026, with verified capacities, viscosities, and oil quality standards for each.
Need an oil change scheduled? Book it at our service department in Fontana, or call our service team at 909-675-1927.
Quick Reference: Ram 2500 Oil Specs by Engine
The 2026 Ram 2500 offers two engines, but the 2010–2026 model run included three across the era. Each has different requirements, and the specifications have evolved over time. The table below is organized by engine generation:
| Engine | Model Years (Ram 2500) | Capacity (w/ filter) | Viscosity | Quality Standard |
|---|---|---|---|---|
| 6.7L Cummins Turbo Diesel I6 (early) | 2010–2018 | 12 quarts (11.4 L) | 15W-40 above 0°F 5W-40 below 0°F (or all-temp) |
API CK-4 + Cummins CES 20081 |
| 6.7L Cummins Turbo Diesel I6 (current) | 2019–2026 | 12 quarts (11.4 L) | 10W-30 above 0°F 5W-40 below 0°F (or all-temp) |
API CK-4 + CES 20081 + Chrysler MS-10902 |
| 6.4L HEMI V8 (early) | 2014–2021 | 7 quarts (6.6 L) | 0W-40 full synthetic | Chrysler MS-12633 |
| 6.4L HEMI V8 (current) | 2022–2026 | 7 quarts (6.6 L) | 0W-40 full synthetic | Chrysler MS-A0921 |
| 5.7L HEMI V8 (legacy gas option) | 2010–2018 | 7 quarts (6.6 L) | 5W-20 standard 5W-30 if GCWR over 14,000 lbs |
Chrysler MS-6395 |
The 2019+ 6.7L Cummins uses hydraulic lifters and is not compatible with 15W-40. The viscosity change at 2019 is an engineering shift, not a preference. Always confirm against your oil fill cap or owner’s manual.
2026 Ram 2500 6.7L Cummins Turbo Diesel I6
The 6.7L Cummins remains the optional powerplant on the 2026 Ram 2500 and is the right choice for heavy towing, fifth-wheel work, and sustained payload duty in and around Fontana, Rancho Cucamonga, and Claremont.
Oil Capacity
12 quarts (11.4 liters) with filter change — applies to every Ram 2500 6.7L Cummins from 2007.5 through 2026. Without a filter change, the engine holds approximately 11 quarts. The 12-quart figure is the same across regular cab, crew cab, and mega cab configurations.
Recommended Viscosity (2026)
Use a full-synthetic 10W-30 diesel oil for operating temperatures above 0°F, or a full-synthetic 5W-40 for all-temperature use including sub-zero conditions. The 5W-40 is the most universally usable choice for owners who tow heavy or operate in mixed climates.
Required Quality Standards
API CK-4 (current diesel service category) plus Cummins CES 20081 and Chrysler MS-10902. Genuine Mopar® diesel engine oil is formulated to all three specifications.
Oil Filter
Always replace the spin-on diesel oil filter at every change. The filter retains roughly half a quart of oil and is sized to handle the soot loading and combustion byproducts that gasoline engines never see. Prime the new filter with a small amount of fresh oil before installing to reduce dry-start time on first crank.
Heads-Up on 15W-40
Many older 6.7L Cummins guides still list 15W-40 as a primary recommendation. That was correct for 2007.5–2018 model years. The 2019 redesign added hydraulic lifters, and Cummins specifically removed 15W-40 from the approved viscosity list. If you own a 2019 or newer 6.7L Cummins, stick with 10W-30 or 5W-40.
2026 Ram 2500 6.4L HEMI V8
The 6.4L HEMI is the standard gas engine on the 2026 Ram 2500. It produces 405 horsepower and 429 lb-ft of torque, paired with the 8-speed automatic.
Oil Capacity
7 quarts (6.6 liters) with filter change. This figure has been consistent from the 6.4L HEMI’s introduction in the 2014 model year through 2026.
Recommended Viscosity
SAE 0W-40 full synthetic — required, not optional. The 0W-40 specification is unique to the 6.4L HEMI and does not carry over from the lighter-duty 5.7L HEMI in the Ram 1500 (which uses 5W-20 or 0W-20 depending on year). Using a thinner oil like 5W-20 in a 6.4L HEMI is a frequent mistake and can contribute to camshaft and lifter wear — issues this engine is particularly sensitive to.
Required Quality Standard
Chrysler MS-A0921 (current for 2022+ model years). Earlier 2014–2021 6.4L HEMI applications carried the MS-12633 standard, which is still backward compatible for those older trucks. For a 2026 truck, MS-A0921-rated 0W-40 is the correct choice. API SP certification meets current passenger car standards but doesn’t substitute for the MS-A0921 designation.
On 5W-30 Substitution
Some owners ask whether 5W-30 is an acceptable substitute. It is not the specified viscosity, and using it where 0W-40 is called for can affect cold-start lubrication of the variable valve timing system and may not provide the high-temperature film strength the engine is designed around. Confirm against your oil fill cap or owner’s manual before substituting.
Oil Filter
Use a Mopar® OEM filter or equivalent. The 6.4L HEMI’s small spin-on filter looks unremarkable but is engineered for this engine’s specific flow rate. Apply a thin coat of fresh oil to the rubber gasket before installation, then tighten by hand three-quarters of a turn past gasket contact (or per the filter manufacturer’s instructions).
Oil Change Intervals: 2026 Ram 2500
Ram’s modern Oil Change Indicator system calculates remaining oil life based on engine temperature, load, RPM, and driving habits. Follow the indicator first — but know the maximum intervals from the owner’s manual:
| Engine | Normal Duty (Maximum) | Severe Duty |
|---|---|---|
| 6.7L Cummins Turbo Diesel | 15,000 miles / 12 months / 350 hours run time, whichever first | 4,000 miles / 350 hours run time |
| 6.4L HEMI V8 (and 5.7L HEMI on 2500/3500) | 8,000 miles / 12 months / 350 hours run time, whichever first | 4,000 miles / 350 hours run time |
A few notes worth flagging:
- The 15,000-mile cap on the Cummins is far longer than the 7,500–10,000 mile figure commonly quoted online. That older interval applied to pre-synthetic-oil eras and is not the current spec.
- Severe duty is 4,000 miles, not 5,000. The 4,000-mile interval applies whenever dust, idling, or low-RPM operation dominates — common for commercial use, construction site work, and dirt-road driving.
- The 350-hour engine run-time threshold matters most for fleet operators and commercial users who idle a lot.
Common Mistakes to Avoid
Mixing up Ram 1500 and Ram 2500 oil specs. The single most frequent error. The 5.7L HEMI in the Ram 1500 uses 5W-20 (2013–2021) or 0W-20 (2022+). The 6.4L HEMI in the Ram 2500 uses 0W-40. Same brand of truck, completely different oil. Always confirm against your own oil fill cap.
Using 15W-40 in a 2019+ Cummins. It’s an old habit from earlier 6.7L Cummins generations, but Cummins specifically removed 15W-40 approval when the 2019 redesign moved to hydraulic lifters. Run 10W-30 or 5W-40 only.
Skipping the filter swap. Replacing oil without replacing the filter leaves contaminated oil circulating through fresh fluid on the first start. Every change. Every time.
Over-tightening the drain plug. Ram’s typical drain plug torque sits around 30 ft-lbs for the 6.4L HEMI and roughly 37 ft-lbs for the 6.7L Cummins, but always verify against your owner’s manual. Over-tightening strips the oil pan threads — a repair that often requires replacing the pan entirely.
Over-filling. Adding “a little extra to be safe” causes oil aeration as the crankshaft whips foamy fluid through the engine. Aerated oil cannot lubricate. Stick to the specified capacity, then verify with the dipstick after the oil has settled for 5–10 minutes on level ground.
Reusing the drain plug crush washer. Some owners overlook this small detail. A fresh copper or aluminum crush washer ensures a proper seal at the drain plug. Reusing a flattened washer is a common cause of slow drain plug leaks.
Why Professional Service Makes Sense
Oil changes look simple on paper. In practice, the 2026 Ram 2500’s two engines have different capacities, viscosities, quality standards, and drain plug torque specs — and the right oil for one is the wrong oil for the other. Fontana Chrysler Dodge Jeep Ram’s certified Mopar® technicians work with these specifications daily and stock the genuine Mopar® oils and filters that match each engine’s exact requirements.
A few things our service team handles as part of every oil service:
- Correct oil grade verification against your specific engine and model year
- Mopar® OEM filter installation with proper torque
- Drain plug torque to factory specification, with crush washer replacement
- Oil Change Indicator reset
- Multi-point inspection covering coolant, brake fluid, transmission fluid, DEF (on Cummins models), and tire wear
Need genuine Mopar® oil or filters for a DIY change instead? Call our parts department at 909-675-1656.
Frequently Asked Questions
How many quarts of oil does a 2026 Ram 2500 6.7L Cummins take?
The 2026 Ram 2500 6.7L Cummins Turbo Diesel holds 12 quarts (11.4 liters) of oil with a filter change. This capacity has remained the same across every model year from 2007.5 through 2026 and applies to all cab configurations (regular, crew, and mega cab).
What oil viscosity does the 2026 Ram 2500 6.4L HEMI require?
The 2026 Ram 2500 6.4L HEMI V8 requires SAE 0W-40 full synthetic engine oil meeting Chrysler MS-A0921 specification. The 0W-40 viscosity is specific to the 6.4L HEMI and is different from the 5W-20 or 0W-20 used in the Ram 1500’s 5.7L HEMI.
Can I use 15W-40 oil in a 2019 or newer Ram 2500 Cummins?
No. The 2019 and newer 6.7L Cummins engines use hydraulic lifters, and Cummins specifically removed 15W-40 from the approved viscosity list for these engines. Use full-synthetic 10W-30 for temperatures above 0°F or 5W-40 for all-temperature operation. 15W-40 remains acceptable only for 2007.5–2018 6.7L Cummins engines.
How often should I change the oil in my 2026 Ram 2500?
Follow the Oil Change Indicator system first. The owner’s manual maximum intervals are 15,000 miles for the 6.7L Cummins and 8,000 miles for the 6.4L HEMI under normal duty (or 12 months or 350 hours of engine run time, whichever comes first). For severe duty (dusty environments, off-road use, predominantly idle operation), shorten to 4,000 miles for either engine.
Is the 6.4L HEMI in the Ram 2500 the same as in the Dodge Charger?
They share displacement and core architecture, but the truck 6.4L HEMI used in the Ram 2500/3500 is a separate engine tuned for torque and heavy-duty durability. The performance-car 6.4L HEMI is a different application. Both require 7 quarts of 0W-40 synthetic, but the truck version’s spec is Chrysler MS-A0921 for 2022+ model years.
Schedule Your 2026 Ram 2500 Oil Service in Fontana
Whether you’re running the 6.4L HEMI for daily duty around Rancho Cucamonga, hauling with the 6.7L Cummins, or maintaining an older Ram 2500 from the 2010–2018 range, our service team in Fontana keeps your truck running on the exact oil specification it was engineered for.
Visit Us: 16263 S Highland Ave, Fontana, CA 92336
Service Department: 909-675-1927
Disclaimer: This guide provides general oil specifications for Ram 2500 engines based on Ram, Cummins, and Mopar® manufacturer documentation. Always verify the correct oil type, viscosity, and capacity for your specific vehicle in your owner’s manual or on the oil fill cap. Specifications can vary by model year, VIN, build configuration, and regional market, and Ram may issue service bulletins that supersede information shown here. When in doubt, call our service team at 909-675-1927 to confirm before performing maintenance.