I’ve spent more than two decades with my hands on Cummins diesel engines — first in a Ram/Cummins dealer shop, later running my own garage — and if there’s one spec I’ve had to correct more than any other, it’s the 6.7 Cummins oil capacity. Forums say 11 quarts. A parts-store clerk will tell you 10. A YouTube video swears by 13. Meanwhile the number printed in your owner’s manual has barely changed since the engine debuted in Ram trucks for the 2010 model year.

Getting the 6.7 Cummins oil capacity wrong isn’t a cosmetic error. Underfill it and you’re starving a turbocharged diesel that makes 400+ lb-ft of torque. Overfill it and you’re whipping the oil into foam, pushing seals, and turning an $80 service into a $4,000 headache. This guide gives you the exact 6.7 Cummins oil capacity for every model year, the oil type Cummins and Ram actually recommend, the correct filter, the fill-and-verify procedure we use in the bay, and the mistakes I still see weekly on trucks that should know better.

Everything below is sourced from factory documentation — the Cummins B6.7 engine specifications, Ram owner’s manuals, and API engine oil standards — cross-checked against the trucks that roll through my own shop. If you’re looking at a different Cummins application (school bus, marine, industrial), the 6.7 Cummins oil capacity can differ; this page covers the Ram truck family that 95% of you are searching for.

6.7 Cummins Oil Capacity at a Glance

Bookmark this table — it answers the entire 6.7 Cummins oil capacity question in ten seconds.

How Much Oil Does a 6.7 Cummins Take? (By Model Year)

One of the friendliest things about the 6.7 Cummins oil capacity is its consistency. Whether you drive a 2010 Ram 2500 or a 2024 Ram 3500, the answer is the same: 12 quarts with a filter change. Ram kept the oil pan and lubrication system fundamentally unchanged across both body styles, which is rare in this industry.

2010–2012: The first-generation 6.7 in Ram

When the 6.7 replaced the legendary 5.9, the 6.7 Cummins oil capacity carried over at 12 quarts. These early trucks (350 hp / 650 lb-ft in most configs) are now high-mileage workhorses. If you own one, pay extra attention to the dipstick after a fill: worn pans and previous over-tightened drain plugs mean some of these trucks drain a little slower, so give the old oil time to fully drip before you pour the new 12 quarts in.

2013–2018: The refined middle years

The 2013 refresh bumped output (up to 385 hp / 850 lb-ft in HO form by 2016) but the 6.7 Cummins oil capacity stayed at 12 quarts. These are the trucks I recommend most often on the used market — and the ones where I most often find overfilled crankcases, because owners top up between services without checking. Twelve quarts is the total; don’t chase the “add one more for luck” myth.

2019–2024: Current generation

The 2019+ Ram brought a new interior and up to 1,075 lb-ft in the HO Cummins, yet the 6.7 Cummins oil capacity remains 12 quarts with a filter. The oil change indicator in the Uconnect screen is genuinely good on these — use it, but never let it override a dipstick that reads low.

Remember the headline: the 6.7 Cummins oil capacity never wavered. Across all three generations, the only real variation you’ll meet is how much comes back out, not how much goes in. A hot, level, 20-minute drain returns roughly 11 to 11.5 quarts; the rest clings to the turbo, cooler and filter housing. That’s normal, and it’s exactly why the fill-and-verify routine below matters.

Why the 6.7 Cummins Oil Capacity Is 12 Quarts

People ask me why a 6.7-liter diesel needs nearly 12 quarts of oil when a 6.7L gas V8 (like Ford’s Godzilla) sips 8 or so. Three engineering reasons, all of which matter to how you maintain the engine:

• Diesel soot and fuel dilution. A diesel’s oil doesn’t just lubricate — it absorbs soot, neutralizes acids from combustion, and suspends fuel that slips past the rings. That job demands volume. The 12-quart 6.7 Cummins oil capacity dilutes contaminants so the oil survives a full service interval.
• Turbo and cooling loads. The 6.7’s turbocharger spins at 100,000+ rpm and is oil-fed and oil-cooled. Add the oil cooler’s charge and the gallery volume, and a big sump keeps pressure stable at hot idle — exactly when a towed 14,000-lb trailer needs it.
• Long-service design. Cummins designed the B6.7 for extended drains in commercial duty. A larger oil volume slows the rate at which additive packages (detergents, dispersants, TBN reserve) are consumed — the same reason heavy machinery runs huge sumps.

So when someone tells you the 6.7 Cummins oil capacity is “too much” and you should fill less to save money, you’re hearing the opposite of engineering intent. The sump size is the feature.

Towing, Idling and the 6.7 Cummins Oil Capacity

That 12-quart 6.7 Cummins oil capacity isn’t a random number — it’s a heat sink. When you’re dragging a 14,000-lb fifth wheel up a six-percent grade in July, oil temperature climbs, and the sump volume plus the oil cooler do the work of keeping the lubricating film intact. That’s precisely why the 6.7 Cummins oil capacity matters most on trucks that work for a living.

Three field notes from my own lot:

• Tow more than you haul? Treat oil temp like a gauge, not a suggestion. Sustained sump temps above roughly 250 °F should shorten your change interval, no matter what the screen says.
• Idling is the silent interval killer. Most OEM formulas count an hour of idle as ~25 miles of engine wear. A truck that idles half the day racks up “miles” the odometer never shows.
• Cold-weather towing is where 5W-40 earns its keep. The 6.7 Cummins oil capacity only protects what can actually flow; a 15W-40 at −10 °F is honey trying to climb a ladder.

None of this changes the fill number — the 6.7 Cummins oil capacity is 12 quarts in every scenario — but it absolutely changes how far you should trust one fill.

Best Oil Type for the 6.7 Cummins

Knowing the 6.7 Cummins oil capacity is only half the answer — the other half is what you pour in. Ram and Cummins documentation converge on the same recommendation for the 6.7 Cummins: a diesel-rated oil meeting API service category CK-4 (or the older CJ-4), with viscosity chosen for your climate.

5W-40 vs 15W-40: which one?

5W-40 synthetic is the all-temperature champion and what I put in every 6.7 that enters my shop, from Phoenix to Fargo. It flows at cold start like a 5W — protecting the turbo and top end in the first ten seconds, when most wear happens — and shears to a tough 40-weight film at operating temperature. 15W-40 remains acceptable above 0 °F (−18 °C) and is what many fleets run because it’s cheap and proven, but in a personal truck there’s no reason not to run 5W-40.

Synthetic vs conventional

Full synthetic isn’t marketing on this engine. Soot handling, oxidation stability during long tows, and cold-crank protection are measurably better, and synthetics hold their viscosity longer across the 6.7’s long drain intervals. If your budget forces conventional 15W-40, shorten your interval — that’s the honest trade.

Buying by the case? Any major-brand CK-4 5W-40 synthetic (Rotella T6, Delo 400 XSP, Mobil Delvac 1310, or Mopar-branded) is fine — the spec on the label matters more than the brand on the cap. And if you cross-shop gas engines, our spec tables on the GarageNumbers home page list oil capacities for the most-searched gas engines too.

Oil Filter Part Numbers That Fit the 6.7 Cummins

Choosing the right filter matters as much as knowing the 6.7 Cummins oil capacity. The engine uses a spin-on full-flow filter mounted on the driver side of the block. Factory and OEM-equivalent options I trust:

• Mopar MO-285 — the dealer filter; you can see it on Mopar’s official parts site.
• Fleetguard LF16015 — Cummins’ own filtration brand (Fleetguard), excellent media and anti-drain-back valve.
• Wix 57632 / Donaldson equivalents — reputable aftermarket with proper bypass pressure specs.

Pre-fill the new filter about halfway, lube the gasket with clean oil, and spin it on hand-tight plus about a half turn — no tools on install, ever. A filter that costs $12 and meets spec beats a $30 “premium” filter that doesn’t list Cummins compatibility. Verify fitment with your VIN before ordering; a handful of medium-duty chassis used alternate housings.

6.7 Cummins vs Power Stroke & Duramax Oil Capacity

Search the 6.7 Cummins oil capacity and you’ll bump into its two rivals within a minute, so here’s the bar-argument settled with numbers:

The Cummins sits right in the middle, and in my experience the difference mostly changes service cost and drain behavior, not durability. The Duramax’s 10 quarts warms and drains fast; the Power Stroke’s 13 quarts gives a little extra margin and a slightly bigger bill. What separates the three isn’t the 6.7 Cummins oil capacity versus a rival’s sump — it’s maintenance discipline. I’ve buried well-kept examples of all three engines, and I’ve towed behind neglected examples of all three.

One honest footnote: Cummins parts and filter availability is superb across North America, and the spin-on filter keeps the 12-quart 6.7 Cummins oil capacity service a 20-minute job instead of a cartridge-housing chore.

How to Check the Oil Level Correctly

Half the “low oil” and “overfilled” 6.7s I diagnose were simply checked wrong. Here’s the procedure that gives a truthful reading:

1. Park on level ground — a driveway slope lies by a quart.
2. Shut the engine down and wait 10–15 minutes so oil drains back from the turbo and head.
3. Pull the yellow-handled dipstick (driver side), wipe it clean with a lint-free rag, and reinsert fully.
4. Withdraw and read both sides; trust the lower mark if they disagree. The level should sit between the add and full marks, ideally at or just under full.
5. If topping up, add in half-quart increments through the fill cap and re-check. Never dump a full quart in blind.

On a hot truck right off the highway, the reading will look low until drain-back finishes — don’t conclude the 6.7 Cummins oil capacity changed; it didn’t. Don’t chase it with extra oil — that’s how a correct 12-quart fill becomes a 13-quart problem.

How to Change the Oil in a 6.7 Cummins (Step by Step)

This is the exact routine we follow in the shop. Budget 45 minutes for a first-timer, 20 once you’ve done it twice.

Tools & materials to have ready

• Ramps or jack stands and wheel chocks
• Correct socket for the drain plug plus a torque wrench
• Oil filter wrench and a drain pan rated 12+ quarts — the 6.7 Cummins oil capacity will overflow a standard 10-quart pan
• Funnel, nitrile gloves, lint-free rags
• 12 quarts of CK-4 5W-40 and a Mopar MO-285 / Fleetguard LF16015 filter

1. Warm it up. Drive 10 minutes so the oil is hot and carries the soot out with it. Hot oil drains nearly completely; cold oil hides in the pan.
2. Lift and secure. Ramps or stands, parking brake set, wheels chocked. Never trust a jack alone.
3. Drain. Remove the pan drain plug (expect ~25 lb-ft on reinstall per commonly published service data — snug, not heroic). Drain into a 12+ quart pan; the 6.7 Cummins oil capacity will surprise a small catch pan.
4. Filter off. Spin the old filter off, catch the residual oil, and wipe the mounting pad clean. Inspect the old gasket — a stuck gasket plus a new gasket is the classic double-gasket leak.
5. Filter on. Oil the new gasket, pre-fill halfway, install hand-tight plus half a turn.
6. Plug in. Reinstall the drain plug with a new washer if yours uses one; torque to ~25 lb-ft.
7. Fill 12 quarts. Pour in 12 quarts of CK-4 5W-40. Yes — the full 6.7 Cummins oil capacity, filter included.
8. Run and verify. Start, idle 60 seconds watching for the filter to seat dry, shut down, wait 10 minutes, and check the dipstick. Top up in half-quarts to the full mark.
9. Reset and record. Clear the oil change indicator in the instrument cluster, log the mileage, and check for leaks after your next drive.

Dispose of the used oil and filter at any auto parts store or recycling point — a single oil change’s worth of diesel oil can contaminate a million gallons of fresh water. It’s the one part of this job where cutting corners hurts someone else.

6.7 Cummins Oil Capacity: DIY vs Shop Cost

Let’s talk money, because the 6.7 Cummins oil capacity directly sets your service bill: 12 quarts is 12 quarts, whether you pour it or a tech does.

• DIY: 12 quarts of CK-4 5W-40 synthetic runs about $90–$110, plus a $12–$18 filter. Total roughly $110–$130.
• Independent shop: typically $160–$200 installed.
• Dealer: commonly $220–$280.

You’re paying for the 6.7 Cummins oil capacity in bulk every single time — a diesel service costs about double a gasser’s, which is exactly why some owners stretch intervals past all sense. Don’t. If the budget is tight, do it yourself: the 6.7 is one of the easiest diesel services in the bay, with a front-mounted filter and a drain plug you can reach without drama on most trucks.

Oil Change Interval for the 6.7 Cummins

Once the 6.7 Cummins oil capacity is filled correctly, the next question is timing. Ram’s official answer is elegantly simple: follow the oil change indicator. The computer models load, temperature, idle time and towing — and it’s honestly calibrated on the 6.7. In the real world, here’s what that translates to in my experience:

• Highway/light duty: 9,000–10,000 miles on 5W-40 synthetic is routine and safe.
• Heavy towing / frequent short trips / lots of idle: 5,000–7,500 miles. Soot and fuel dilution climb fast when the engine never fully warms.
• Conventional 15W-40: cut those figures roughly in half.

If you tow a fifth-wheel through mountains every weekend, ignore the 10k optimism and change at 5–6k. Oil is the cheapest insurance a diesel offers; the 12-quart 6.7 Cummins oil capacity makes each service about $90–$130 in synthetic. Compare that to a turbo or bearing job and the math writes itself.

7 Mistakes That Kill a 6.7 Cummins

After twenty years, the failures I see around the 6.7 Cummins oil capacity are rarely exotic. They’re the same seven errors, over and over:

1. Overfilling past the full mark. Foaming, seal pressure, and a turbo breathing oil mist. The 6.7 Cummins oil capacity is 12 quarts — not “12 plus whatever’s left in the jug.”
2. Using gas-engine oil. An API SP bottle in a diesel is a slow-poison decision; soot overwhelms the additive package.
3. Cheap no-name filters. Bypass valves stuck open circulate unfiltered oil; that’s bearing sandblasting.
4. Cold-revving after startup. Thirty seconds of idle beats thirty seconds of throttle for turbo bearing life.
5. Ignoring small leaks. A rear main or cooler seep that loses a quart over a month is a low-oil event you scheduled.
6. Extending drains on conventional oil while towing. The indicator assumes the oil you told it about; lie to it and it lies back.
7. Skipping the post-fill dipstick check. Every engine drains a little differently. The dipstick is the only witness that matters.

6.7 vs 5.9 Cummins Oil Capacity

Older readers will remember the 5.9L 24-valve Cummins (1998–2007), which also held about 12 quarts with a filter. So the headline number didn’t change when displacement grew — but nearly everything around it did: the 6.7 added a variable-geometry turbo, higher injection pressures, and tighter emissions hardware, all of which raise the stakes on oil quality even though the 6.7 Cummins oil capacity matches its predecessor. If you’re swapping generations or buying used, treat the 5.9 as tolerant and the 6.7 as precise: same quarts, higher standards.

Signs Your 6.7 Is Low on Oil

The 6.7 will talk to you before it dies. Listen for:

• Low-oil message or gauge drop in the cluster — obvious, but people drive through it.
• Increased turbo lag or whine — the turbo is first in line for oil pressure.
• Top-end tick at hot idle that quiets after a top-up.
• Oil smell or smoke after hard running — check for leaks at the cooler and turbo feed line.

If the dipstick reads below the add mark, top up immediately in half-quarts and then find out where it went. A healthy 6.7 shouldn’t drink oil between full 6.7 Cummins oil capacity services; if yours does, our contact page is open and so is every diesel forum you trust — but start with a compression and leak-down test before assuming the worst.

The Bottom Line

Fourteen years of production, three body styles, one number: the 6.7 Cummins oil capacity is 12 quarts (11.4 L) with a filter change, filled with API CK-4 5W-40 synthetic, verified on the dipstick after a ten-minute drain-back. Get the 6.7 Cummins oil capacity right and that sentence is the entire religion. Buy a good filter, warm the oil before draining, torque the plug sensibly, and let the indicator — not the internet — pace your intervals within the ranges above. Do that and the 6.7 will outlive your truck’s paint. For more verified specs — towing capacities, bolt patterns, and oil capacities across gas and diesel engines — browse the tables on GarageNumbers.com, read the latest guides in our blog, or learn how we verify every number. The dipstick always gets the final word. Save this page, share it with your fleet, and keep servicing smart.

Sources & Evidence

Every figure on this page was checked against the following primary sources:

• Cummins B6.7 engine specifications — Cummins Inc.
• Ram Trucks official site — owner resources & towing/engine data
• API Engine Oil — service categories CK-4 / CJ-4 explained
• Mopar — OEM parts (MO-285 oil filter)
• Fleetguard — Cummins filtration (LF16015)

Figures can vary slightly by configuration and production run. Always confirm against your owner’s manual; see our disclaimer.