The oil filter on the G63B engine in the D50/MM is the same as the filters used on Mitsubishi Lancers. Here are the specs on the filter -

Seam Diameter87.00mm
Overall Height100.00mm
Seal Outside Diameter66.00mm
ThreadM20-x1.5-6H

If you use the above specs but source an alternative filter with a height greater than 100mm you'll end up with a filter with a bigger filtering capacity. Anything that prolongs the life of the oil will help. I don't know if they are available in the US but I have always used RYCO oil filters and I've never had a problem with them.