Thanks for the advice guys.
I think especially as this will be the first time I will be changing over to a synthetic I will only do 7500 km as I've heard that the previous mineral oil can contaminate. I will hopefully get an UOA then and will have a better idea of how things are going instead...
My manual (Hyundai Trajet) recommends that I do OCIs at the 15000 km (9300 Mi) mark. This seems pretty extended so I am comtemplating using synthetic especially Mobil 1 using either the 15w-50 or 10-30 as the never gets below 0 degrees C or 32 F here and the lowest it would get is probably 5C or...
