What's the difference between AW32 and AW46 , does It matter which one I use ? This is why I think I need to change it ,looks pretty milky. As some of you may know I just bought this the other day off craigslist used. It seems to run and operate properly but this fluid does it look so good . So when I change it how do I get it all out? I was doing some searching to find out what filter I need to replace it with, and I am finding conflicting answers, some people say don't buy a frame it is junk, anyway I have picked out a couple of wix filters, win 51551 is a 10 micron, win 51553 is a 33 micron, so which do I want to buy??