The Oil Filter Thread
 

I know a popular upgrade to the Miata oil filter is the one off the Millennia. So a while back I was in my local NAPA asking questions about oil filters and the guy kept referring back to this book. What’s that book? I asked. He said it was NAPA’s Filter Reference Guide. It covers just about everything made.
With this guide filters can be looked up many different ways, but the one that makes sense for us is the page that has all the 20x1.5mm thread pitch for our cars. This page lists most of the important features including dimensions, O-ring size, the bypass psi, etc. Listed below is the page and highlighted are some of the other possible choices that would fit a Miata. I choose everything from the stock Miata filter up to the largest choice available to fit with an oil cooler sandwich adapter. So depending how much room you have to work with you can choose a filter that has more media and still uses the same bypass and micron size.
You can get the micron filter size by taking the filter part number from the reference guide and going to the Wix Filter site. By putting in the part number, Wix will list the same filter info plus how many microns down it will filter to. Armed with a larger selection of part number choices, this means more choices in brands NAPA silver, Gold, Platinum, Wix, Amsoil, Mobile One, etc.

https://www.miataturbo.net/attachmen...ine=1359340189

Here's the list from the guide.
https://www.miataturbo.net/attachmen...ine=1359340189

Here's what the sizes look like:
https://www.miataturbo.net/attachmen...ine=1359340189
https://www.miataturbo.net/attachmen...ine=1359340189

Now, the exception is the filter on the right, the 551318. This filter is almost the same as the others except for the by-pass, it takes 4 more psi to make it work (16 psi). This is the filter I will be using and I believe that the difference in by-pass pressure shouldn't be an issue. I hope this info helps, thanks for looking.
Cheers,
-JB

Interesting. Any clearance issues with the big filter on the right?

Holy shit that's a giant filter.

I still haven't used anything beyond the OEM size. I need to look into this next time I do a change. I think I want 1347, or the 2nd one from the left.

The one on the far left is OEM size, yes?

None, although it goes in and out in these space next to the alternator.
Here's the stock one:
https://www.miataturbo.net/attachmen...ine=1359341962
And the 551318
https://www.miataturbo.net/attachmen...ine=1359341962

Is it the angle of the pic or is that freaky close to hitting at the end? Looks like at that angle if the motor mounts allowed any movement that thing would hit.

Edit: Also I like the one second from the right. Looks to be similar size to what you used with a little bit more clearance for oil cooler sandwich plates being thicker or other things. #1626?

Did the rx8 filter come up in this? The rx8 filter is a touch longer than the miata one, but with a much higher bypass pressure. So it basically starts filtering the oil sooner during cold start. The bypass basically defines the max pressure differential allowed across the filter media. As long as the whole filter was taken into consideration when the stiffer bypass was added in it shouldnt cause an issue. Though I'm assuming that on a relatively clean filter on the miata the bypass will be closed, and that you change your oil filter regularly. If you get the filter really clogged up, increasing the bypass pressure could potentially cause a lower pressure issue, but it would at worst be the difference in bypass pressures between stock and your filter. If 4 psi is enough to kill your engine then your oiling system was pretty marginal anyways.

Also, from what I've seen, cars that come from the factory with higher flowing fuel systems use higher bypass filters. The rx8, subarus, some WV all have very high flow pumps, and they all have very high bypass pressures in the filters, hell the 1.8T wv engine has a 33psi bypass.

There's about 3/4" clearance. I would think that would be plenty. If I saw paint rubbing on the filter, then I definitely would choose a shorter one.

Nice to hear that 4 psi is no big deal. It's a new motor with a Boundry pump. The ref guide goes by part number. One section gives a general brand like Ford, Mazda, VW, etc. There wasn't a section to look up a year model car. Different book I suppose.

Let us know if the paint scratchs. Comp mounts? Maybe a vertical pic?

My filter is that tight in there.

Subscribed. I always just used PureOne Millennia filters with a rare earth magnet stuck on the end.

I have a shot from above but it really doesn't show the gap. Too much stuff/manifold in the way. I recommend buying 2 or 3 choices and see which one fits best for your set up. Then just return the ones you didn't like. I got 8 of them here and 7 are goin back.

For some time i use a Opel(GM) oil filter that was bigger than the mazda OEM, right at the star the oil pressure gauge read less pressure, than with the mazda OEM

1083 is 21 microns
1344 is 21 microns
1347 is 21 microns
1626 is 21 microns
7356 is 21 microns
1318 is 21 microns
1365 is 21 microns

Wow. I'm running the PL14459 which crosses to a 31334 Napa. Fits with the factory brace.

Oil Filter Height (Inches) : 3.194"
Oil Filter O.D. (Inches) : 3.252"

The drainback valve is 9-11 PSI. Been working fine on my car, cold start knock kept to a minimum. The PureOne Purolator is 20 micron.

Edit: Uh, might be a newb question, but the 551318 is coming up as a fuel filter in searches. Will this work as well with oil? Nevermind

Thanks for all this info. I was just wondering before last weekend's oil change what larger filters would fit.

I don't know, the "L" in the category is for lube. Try the cross reference with just the 1318 number.

Found it. Napa Gold 1318 crosses to Wix 51318 and has listed applications of certain John Deere Loaders and Yanmar Marine Engines. Sounds like a HD bugger. Purolator does not have an interchange. Seems it's not a terribly common filter.

The 1216 cross to a Wix (bet you can't guess) 51216 and lists some of the Eagle DSM cars, the 91 Dodge Monaco :giggle:, and 87-93 Jeeps, probably depending on equipment. This should be on the shelf most errywhere.

The PL14459 (Wix 51334) is shorter than the second one from the left, but just skinnier than the one second from the right. It's the filter for any year Acura Integra and numerous other import products.

This is the fitment that I used to use on my turbo '92, mostly because after I sold my Integra I had a filter left over, and I realized that it fit the Miata nicely. I'm pretty sure that filter was spec'd on all of the Honda b18 series engines.

What makes a bigger filter better? I was surprised to find the same filter is used for a turbo 2.5l Subaru as our little 1.8. My new Nissan 4.0l v6 uses one that is only .59" taller with the same OD and it's even good for 7500m OCI. Are there any UOA reports that show a bigger filter provides better or longer lasting filtration?