Checking the archives , there was a number of negative posts on Amsoil oil "filters" even though Amsoil oil was preferred over Harley oil. Any recommendations on oil filters for a 2018 Harley ?

 

(1) Harley (OEM), or (2) K&N...

 

I have always just used the OEM, I know its the right one and price is under 12bucks.

 

Here is an ongoing poll of what oil filters HDF members use.

https://www.hdforums.com/forum/oil-a...o-you-use.html

 

Though I have nothing to do with Amsoil, (purely because I don't support MLM schemes), I'm nonetheless surprised that their filters are in question. I was under the impression that for a disposable filter, Amsoil's were among the very best, rated at 17 microns absolute, I believe. I run a high flow permanent filter rated at 22 absolute which is considered above average as filters go.

Anyhow, you have lots of choices, unless you ask a Dealer,,,.

 

I have used permanent oil filters with a uniform screen mesh offering 5 microns absolute. I am aware that paper filters vary greatly due to the material's lack of uniformity, but 17 and 22 sound scary to me. Perhaps I am missing something here.

 

I've never heard tell of a 5 micron absolute filter. I'm not saying they don't exist but just that the only 5 micron rating I'm aware of is "nominal". Therein lies the rub. Nominal filter ratings are a meaningless industry construct which can't even be used to compare the efficiencies of 2 different nominally rated filter brands.

For example,, one way of qualifying a 5 micron filter, using one of a multitude of nominal methods, is to start with a solution containing a known quantity of 5 micron particles and circulating the solution through the filter 1,2,3,4,,,x times until the solution's 5 micron content is reduced by 50% !!! Bingo,, your filter is 5 micron rated. During such a test, 100 micron particles may have been circulating through the filter but this isn't taken into consideration. Only the eventual reduction of 5 micron particles by half, matters.

Absolute ratings aren't entirely "absolute" either but the process is a damn site closer to proving a filter's real world capabilities than the "nominal" methods are. Another method known as "Beta" somethingorother, is an even better rating but I don't think its used much for automotive filters, if at all.

Its been said that 20 years ago the automotive standard for paper filters was 20 microns. Now its 5 microns and the filters haven't changed.

 

I second that.

 

the knock on amsoil filters wasn't the quality, it's they have less filtering media than HD or K&N...I stopped using K&N when they moved production out of the US...stock HD for me now.

 

I can't find any spec sheet as I look, but both my bikes had this type of filter, but they may have come from different manufacturers. The screen mesh has uniform flow rates, unlike paper. That is why filtration does not vary from spot to spot within the element.

https://www.google.com/url?sa=t&rct=...qV96wEube-JIb0