This started as a cheap $2.54 experiment, I had never tried one of these and the "combo" valve intrigued me so I thought I'd give it a shot.
Here's a thread I did that explains the Silvers somewhat when I first started experimenting.
Original Napa Silver thread
I figured it would be another 500 mile experiment and I could add this to the long list of filters my Jeep didn't like. NOPE! I ran this Napa Silver 41085 for 3,200 miles, mostly with Trop Artic 5w30. It was subjected to quite a few weather swings including some -10 below abuse (which is as cold as it will ever get here). This filter ran and started better for me than any filter I've ever tried, including my pet Motorcraft FL-400s. I was mighty surprised but that is why you experiment.
On to the carnage.
Typical Wix manufacture base plate
This shows how the combo valve sits in the center tube. This is one of the more interesting points. The combo valve goes right in and is just a smidge undersized for the center tube. This will allow a little bit of oil past the valve at all times. At first I thought this was sloppy manufacture. After looking it over multiple times and stewing on it for a few days it hit me, it HAS to be that way. The tiny oil flow past the valve is what it needs to allow consistent reliable further opening of the valve if pressures get too high. Brilliant once I figured that out. If the valve "plugged" the center tube, it would be difficult or impossible to regulate when it actually opened further, and failure to open at all could be a possibility. As designed, those issues appear to be eliminated.
Here's another shot of the portion of the combo valve that actually slides down into the center tube. The ADBV sits snugly around the threads.
Here's a shot of the media cartridge. Metal endcaps as you'd expect from Wix, and a whopping 60 pleats of media. A huge amount for a "budget" filter. There is a trade off, the media is quite thin and my guesstimate would be efficiency ratings are fairly low. The media cartridge was measured a 2.5", a little shorter than I would have expected, but more on that later.
Here's the seam side. There was some waviness but everything was solid, the glue seam very tight also I'd have needed a knife to get it apart.
Here's the typical Wix coil spring and the bottom endcap which is fits into to stay secure. I definitely like the spring design! This filter was under far more compression when I opened it than any leaf spring filter I've dissected, it literally smashes the nitrile ADBV into the base plate hard. No wonder it held the oil up so well and gave me such great starts. The downside though, the spring takes more room than a leaf spring and the length of the media suffered as a result. By comparison calculations with other filters, the coil spring costs about a 3/8 of an inch of media space.
Inside the can. I think the grit is likely from opening with a hacksaw, although when I pulled the pleats away from each other carbon grit the filter had caught was visible. I've gotten so proficient at opening filters with a hacksaw I can't justify buying a filter cutter.
Here it is all laid out.
Here is the media cartridge compared to my pet FL-400s. The FL-400s was longer, the Napa had more pleats and the pleat depth was a quarter inch deeper per pleat on the Napa than the Motorcraft.
All in all I found this filter to be an incredible value (typically about a buck less than the Motorcraft) as well as a very interesting design. It worked so well for me I will use one again soon, however the next one will be the oversize 31515 which has an additional 1.5" of media but is otherwise identical. If I didn't have a filter stash to work through I'd happily use these exclusively.
My conclusion is these are a relatively high flow, moderate efficiency filter with an incredibly well sealing ADBV, and of surprising quality for the price. Good job Wix!
Here's a thread I did that explains the Silvers somewhat when I first started experimenting.
Original Napa Silver thread
I figured it would be another 500 mile experiment and I could add this to the long list of filters my Jeep didn't like. NOPE! I ran this Napa Silver 41085 for 3,200 miles, mostly with Trop Artic 5w30. It was subjected to quite a few weather swings including some -10 below abuse (which is as cold as it will ever get here). This filter ran and started better for me than any filter I've ever tried, including my pet Motorcraft FL-400s. I was mighty surprised but that is why you experiment.
On to the carnage.
Typical Wix manufacture base plate
This shows how the combo valve sits in the center tube. This is one of the more interesting points. The combo valve goes right in and is just a smidge undersized for the center tube. This will allow a little bit of oil past the valve at all times. At first I thought this was sloppy manufacture. After looking it over multiple times and stewing on it for a few days it hit me, it HAS to be that way. The tiny oil flow past the valve is what it needs to allow consistent reliable further opening of the valve if pressures get too high. Brilliant once I figured that out. If the valve "plugged" the center tube, it would be difficult or impossible to regulate when it actually opened further, and failure to open at all could be a possibility. As designed, those issues appear to be eliminated.
Here's another shot of the portion of the combo valve that actually slides down into the center tube. The ADBV sits snugly around the threads.
Here's a shot of the media cartridge. Metal endcaps as you'd expect from Wix, and a whopping 60 pleats of media. A huge amount for a "budget" filter. There is a trade off, the media is quite thin and my guesstimate would be efficiency ratings are fairly low. The media cartridge was measured a 2.5", a little shorter than I would have expected, but more on that later.
Here's the seam side. There was some waviness but everything was solid, the glue seam very tight also I'd have needed a knife to get it apart.
Here's the typical Wix coil spring and the bottom endcap which is fits into to stay secure. I definitely like the spring design! This filter was under far more compression when I opened it than any leaf spring filter I've dissected, it literally smashes the nitrile ADBV into the base plate hard. No wonder it held the oil up so well and gave me such great starts. The downside though, the spring takes more room than a leaf spring and the length of the media suffered as a result. By comparison calculations with other filters, the coil spring costs about a 3/8 of an inch of media space.
Inside the can. I think the grit is likely from opening with a hacksaw, although when I pulled the pleats away from each other carbon grit the filter had caught was visible. I've gotten so proficient at opening filters with a hacksaw I can't justify buying a filter cutter.
Here it is all laid out.
Here is the media cartridge compared to my pet FL-400s. The FL-400s was longer, the Napa had more pleats and the pleat depth was a quarter inch deeper per pleat on the Napa than the Motorcraft.
All in all I found this filter to be an incredible value (typically about a buck less than the Motorcraft) as well as a very interesting design. It worked so well for me I will use one again soon, however the next one will be the oversize 31515 which has an additional 1.5" of media but is otherwise identical. If I didn't have a filter stash to work through I'd happily use these exclusively.
My conclusion is these are a relatively high flow, moderate efficiency filter with an incredibly well sealing ADBV, and of surprising quality for the price. Good job Wix!