Do you guys just go to your local dealer, or dept. store and buy stock filters? I want to switch to foam air filters where ever possible (thanks Rob; dern can of worms you opened up, you know). The local dealer probably won't be able to help me as the only thing most will have is "the part number" item in inventory. I have not axed Dr Google about this as I always get off on other fascinating tangents, thereby _not_ accomplishing what I started off to do. Same with the oil filters, when it comes to efficiency. In the article Rob linked to, or in the on-line oil bible, one or the other, they gave tables and tables of mfr.'s filters and their numerical scores. I did not see a drastic difference in the numbers, but I may as well get the ones they ranked high. I don't want to reinvent the wheel if possible, but I do want to find a supplier who carries the special items.