“Peace of mind,” you say. Yeah, put a price on that. I’m in your camp on that.As most of you DIY owners know, Mazda in their infinite wisdom decided to source their current 2.5 Turbo oil filters from Thailand, instead of the original Tokyo Roki units from Japan. Other manufacturers have done this in the past, Toyota went to Thai sourced filters some years ago (denoted by a YZZ in the part number) and Honda changed from a Filtech manufactured unit (A01) to the A02 manufactured by Fram (gasp!). Why are they doing this? PROFITS! All of the redesigned filters are made more cheaply than the originals, and therefore have a larger profit margin. I have managed to purchase 30+ Tokyo Roki filters (part number PY8W-14-302) which should get me through 150,000 miles on my newly acquired Mazda 6. I also ended up with a few of the crappy Thai replacements (from an eBay supplier that assured me they had a large number of the originals, and then sent me the crummy ones). The new part number is 1WPY-14-302.
I dissected both filters and took a bunch of photos.... View attachment 239163 View attachment 239164
First the boxes...not much difference, but the Japanese filter comes in a box with glued flaps for additional security, although both filters had shrink wrap plastic over the business ends. The inner flaps had installation instructions, interesting that the Japanese filter called for tightening 1 turn after contact, whereas the Thai filter called for the more common 3/4 turn.
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Here's a side view, not much difference here, although the Japanese filter has a little shinier finish. Both are marked with the double line denoting these filters are for the Turbo engines.
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The bottom view shows the first major difference...diameter. The Japanese filter is larger at ~66.8 mm, whereas the Thai filter is ~64.2 mm. Those of you who have been using a cup wrench on your filters will need to buy a smaller one. They both have 14 flats.
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The top view shows some interesting differences...the Japanese filter has 6 6mm round holes, whereas the Thai filter has eight elongated holes 4mm wide. A rough estimate of total area shows the Japanese filter at 169.6 square mm total area, with the Thai filter at 228.5 square mm total area. That would indicate the flow rate of the Thai filter is higher. Another difference is the mounting boss of the Japanese filter is thicker and has 5 screw threads, the Thai filter only has 4 threads. You can see the filter element pleats on the Thai filter directly through the holes, the Japanese filter has metal end caps on the element.
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The Japanese filter weighs 217 grams, the Thai filter is lighter at 165 grams. Weighing the individual parts after disassembly shows the significant differences were in the mounting bosses (Japanese-96g, Thai-77g) and the internals (Japanese-73g, Thai-44g).
View attachment 239171 The Japanese sealing gasket is more robust than that on the Thai filter, that may explain the extra 1/4 turn specified for tightening. Both gaskets have a ridge at the bottom that locks them into a groove on the mounting boss to prevent them from coming loose during installation or removal.
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Here are both filters disassembled...the Japanese filter has metal end caps on both ends of the element, and uses a rubber gasket on the center hole to seal the element against the mounting boss. The bypass valve is built into the lower end cap on the Japanese filter, whereas it is in the tensioner spring on the Thai filter. Neither filter has an anti-drainback valve, however it is not needed since the filter hangs vertically down from the engine.
So what are we to make of all this? The only possible advantage I see in the new filter is the increased oil flow rate from the larger holes in the mounting boss. Everything else in the Thai filter seems cheaper. Of course the new filter must have been approved for use by a Mazda engineering group, and they aren't about to jeopardize longevity of their engines for the sake of a little more profit from each filter. On the other hand, they could only be concerned with average longevity for the first owner/lessee, which might only be 50,000 miles or so...those of us who buy used or who keep their cars for over 100,000 miles might end up screwed in the end. The moral is...if I only had the Thai filters at my disposal, I would change them every 2,500 miles (and top up the oil) and drain the sump every 5,000 miles. Overkill? Maybe, but at least I would have peace of mind!