Depends on the oil change intervals, subaru recommends every 7500km\'s max, most "its just a car owners" will only do every 10000kms.I change mine every 5000kms on my 04 which has done 185000kms without a problem.
As far as 5w-30w oils go, dont use them if you like to use your subaru in the high rev range, you are likely to damage a big end bearing, 5w-30w is just to thin.Subaru recommends it for "normal" driving because it gives better fuel economy.If you go to a subaru dealer and ask what oil for high rev driving, they will give you 10w-60w.
Lots of info, thanks.Manual is td04hla-19t.I\'ve managed to source a complete brand new rolling center assembly, so it will be an easy swap into the housings