No not really, it doesn't really make the oil last longer. These strainers in the sump have quite a large mesh as you can see. Its main function is to ensure that any large bits that might be in the oil don't get sucked into the pump. Also, in some cases they ensure a proper even inlet flow into the pump.
Obviously, they do some straining as well, but the real oil filter does a much better job at that. Check the manual and see if says anything about regular maintenance/cleaning. chances are its not mentioned in the regular maintenance schedule at all for these reasons.
Jeroen |