apparently Penrite Synthetic 5 (5W-60) is one of the best oils you can use, i havent tested it yet but i will do soon.. its about $70 for 5 litres but from what ive been hearing it seems to be worth it
hepburn heights bushland is alright and theres an alright jump in there to... only reccomend it if you live near by though otherwise not really worth it.