Dodge RAM 6.7L Cummins · Model Years 2010–2024
If you've been using a WIX fuel filter on your 6.7L Cummins and recently switched to a Doc's Diesel filter, or vice versa, your first reaction was probably something like: "These can't possibly be the same part." We get it. The difference in appearance is dramatic. This post settles it once and for all.
They both fit. Full stop.
Despite looking completely different, the Doc's Diesel DGF401, the OEM filter, and the WIX filter all fit the same application: the Dodge RAM 6.7L Cummins diesel engine, model years 2010 through 2024. The confusion is understandable, but the fitment is identical.
Pro tip: Doc's Diesel filters meet or exceed OEM specifications and do not void your factory warranty. They're engineered to OEM standards, not just dimensionally compatible.
The opening that throws everyone off
Here's where the visual difference becomes obvious. The WIX filter has a very large, wide-open opening on the mounting face. Doc's Diesel and the OEM filter both feature a smaller oval opening, but don't be fooled. If you look inside the WIX filter's large opening, there's a round rubber ring seated inside that creates the actual sealing surface. All three filters ultimately interface with the engine in the same way.
One look, three very different appearances: same fit every time
When you set a Doc's DGF401, an OEM filter, and a WIX filter side by side, the WIX immediately stands out. Doc's and OEM both feature a smaller oval-shaped opening on the mounting face, clean, tight, and immediately familiar if you've ever changed this filter before. The WIX, on the other hand, has a dramatically larger, wide-open rectangular face that can make you question whether you grabbed the right part off the shelf.
Here's the key: look inside that large WIX opening, and you'll find a round rubber ring seated inside it. That inner ring is the actual sealing surface, functionally equivalent to the oval opening on Doc's and OEM. All three filters interface with the engine the same way. The fitment is identical across Doc's DGF401, the OEM filter, and WIX for the 2010–2024 Dodge RAM 6.7L Cummins.
The inner rubber ring inside the WIX filter's large opening acts as the functional seal, similar to the oval opening on Doc's and OEM. It just looks vastly different from the outside, which is where the confusion comes from.
Where Doc's Diesel pulls ahead
Same fitment doesn't mean same quality. The construction differences between Doc's DGF401 and a comparable WIX filter are significant, especially if your truck works hard or sits in extreme climates.
Fuel Filter Comparison
6.7L Cummins · Dodge RAM 2010–2024 · DGF401 vs OEM vs WIX
Doc's DGF401
✓ Best Choice
Fitment
2010–2024 RAM 6.7L
Filter Media
3-Layer
O-Ring Type
HNBR
Temp Resistance
Extreme temps
Opening Style
Oval (OEM-match)
Warranty
OEM-compliant
OEM Filter
Fitment
2010–2024 RAM 6.7L
Filter Media
Standard
O-Ring Type
OEM spec
Temp Resistance
Standard
Opening Style
Oval
Warranty
Factory
WIX
Fitment
2010–2024 RAM 6.7L
Filter Media
2-Layer
O-Ring Type
Standard NBR
Temp Resistance
Can crack/stiffen
Opening Style
Large (inner ring)
Warranty
Standard
The O-ring difference matters more than you think
The WIX filter uses a standard NBR (nitrile butadiene rubber) O-ring. NBR works in normal conditions, but under prolonged heat cycling, something a diesel pickup sees every day, it can become brittle or crack over time. A compromised O-ring means a compromised seal.
The Doc's DGF401 uses an HNBR (hydrogenated nitrile butadiene rubber) O-ring. HNBR is specifically engineered to withstand extreme temperatures and harsh fuel environments. It resists cracking, maintains elasticity longer, and ensures a tighter, more reliable seal over the life of the filter.
3-layer vs. 2-layer media
More filtration layers means finer contamination capture and longer service life. The Doc's DGF401 uses a three-layer filter media construction versus WIX's two-layer design. This translates directly to better fuel cleanliness reaching your injectors, critical for the precision tolerances inside a 6.7L Cummins fuel system.
HNBR O-Ring:
Resists extreme heat and cold. Won't crack or go brittle like standard NBR.
3-layer media:
More filtration stages versus WIX's 2-layer design for cleaner fuel to your injectors.
OEM-style opening
Oval face matches factory design for a tighter, more intuitive seal at installation.
Warranty safe
Meets or exceeds OEM specifications — no warranty concerns switching from factory.
Bottom Line:
Don't let the WIX filter's dramatically different appearance spook you, it'll fit your 6.7L Cummins just like the others. But if you're choosing between them, the Doc's DGF401's HNBR O-ring and three-layer media construction deliver a measurable edge in durability and filtration performance, at a price that doesn't require a dealer visit.
Questions about the DGF401 or any other Doc's Diesel filter? Reach out; we're diesel people and happy to help you spec the right part for your application.
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