Your really killing yourself on short oil change intervals, the WIX filter is good on just about any gas engine for around 12000km. And as far as oil goes if your using CH-4/SL or CI-4/SL Rated oils then there is abolutely no reason to be changing it till around 10000km to 12000km and that's the dyno stuff. If you use a synthetic (Group III and up) 12000km is what you should look for.

CH-4/SL or CI-4/SL oils will have a high TBN that will still be perfectly good at that oil change interval and still have plenty of the additive package left in it. Now if your using low end SL or SM oil that's a different story.

With the proven source of availible engine oil anylisis you can look up you can clearly see there is no reason to run your oil or filter for such short durations. Changing oil based off of common schools of though are just not accurate.

WIX is a higher end filter so feel good with going 12000km with it.