I tend to get the cheapest motor oil at repco or autobarn when it comes on special - Nulon 15w40 last time, Gulf Western before that. 5L for $10
If the oil in them isn't disgusting, I will get it going and run for 5 mins, drop the old oil, add 600ml of new, then use it and possibly drop it again.
It all depends on how neglected it previously was.
Often, if it gets replaced again, 15w40 or 10w30 (castrol magnatec or ultraclean) goes back in - I don't usually use sae30
My grandfather has run 15w40 Shell or Castrol in his mowers for years and he bought a Masport with xm50 quantum in 1999, and it runs as good as the day it came out of the factory (doesn't see much use now though)
Last edited by Tyler; 23/09/19 03:30 PM.
