My preferred oil filter is now manufactured in China, but I discovered a superior alternative.

      Andrew P. Collins

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      With nine different gas-powered vehicles on my property, I spend a significant amount of time changing fluids and filters. I don't have a strong brand loyalty when it comes to consumables, but NAPA Gold oil filters have been my preferred choice. They’re reliable, easily found, and until recently, manufactured in the USA. However, when I went to stock up for my Montero’s next oil change this month, I was disappointed to find “made in China” on the box of my NAPA Gold 1334 filter. This led me on a little exploration that ultimately introduced me to a new product that I’m now more enthusiastic about.

      The fact that NAPA has moved its filter production overseas isn't exactly new information. The auto parts retailer switched suppliers from WIX to Premium Guard back in 2023, and this change has been the topic of conversation on forums for years. I suspect I’ve been purchasing old stock of the 1334 size used by my Montero for my last couple of oil changes—or maybe I just didn’t pay close attention to the packaging previously.

      Nonetheless, this prompted me to reassess my filter choices, and I was reminded of a brand called Baldwin, which I had been meaning to investigate.

      Baldwin is a well-established filter brand (air, oil, etc.) used in agricultural and industrial applications and has been for many years. In fact, when I first acquired my Montero in 2018, a fellow owner recommended Baldwin filters to me. But I sort of forgot about it since you hardly ever find them on the shelves of auto parts stores. (For no particularly logical reason, I prefer to buy my oil, filters, and drain-plug kits in person at a physical store.)

      The Baldwin filter for my 1998 Mitsubishi Montero’s 3.5-liter V6, B7243, was much harder to find than the common oil brands typically advertised—they're primarily available at industrial supply websites rather than auto parts outlets. Walmart can also get you one. They're very affordable and, to my delight, still produced in the USA.

      When my Baldwin filter arrived, I noticed it was taller and skinnier, while the NAPA Gold filter appeared shorter and squatter, relatively speaking. They felt similar in weight, but a comparison of their specifications revealed some significant differences.

      Baldwin B7243 vs. NAPA Gold 1334:

      - Height: 3.44" (87.3mm) vs. 3.19" (81mm)

      - Outer Diameter: 3.03" (77mm) vs. 3.25" (83mm)

      - Thread: M20 × 1.5 for both

      - Bypass Valve: 20 PSID vs. 8–11 PSID

      - Micron Rating: 18 nominal / 40 absolute vs. 21 nominal

      - Media: “Microlite” (Baldwin proprietary) vs. Glass-enhanced cellulose

      - OEM Cross-reference: Mitsubishi MD352626, MZ690116 for Baldwin vs. Generic fit for NAPA

      Here are the key three takeaways from the information I gathered about these filters.

      1. The gap in the bypass valve is significant. A difference of 20 PSID compared to 8–11 PSID isn't negligible—it's nearly double. The B7243 has both an anti-drainback valve and a 20 PSID bypass valve. A filter that bypasses at 8–11 psi will redirect unfiltered oil past the element under relatively low differential pressures—for instance, during a cold start in winter when the oil is thick or when the filter is somewhat loaded. The Baldwin maintains its performance until hitting 20 psi. For a hardworking V6 in a 4×4 subject to varying conditions, this is truly advantageous.

      2. The Baldwin filter has a finer micron rating. The B7243 is rated at 18 micron nominal, while the NAPA Gold is rated at 21 micron nominal. Baldwin also provides an absolute rating of 40 microns, which is a stricter standard (nominal ratings allow a percentage of particles to pass; absolute means nearly no particles above that size can get through). The NAPA does not disclose an absolute rating at all, which suggests something significant.

      3. The Baldwin filter is designed specifically for application use, not as a generic option. The B7243 directly replaces Mitsubishi OEM part numbers MD352626 and MZ690116—these are the actual factory filter numbers for your engine. The NAPA 1334 corresponds to 559 different filters across cars, trucks, tractors, and industrial machinery. It fits the Montero but wasn't engineered specifically for it. The B7243 was.

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