I have a my94 uk wagon with a full subaru service history 102,000 miles.
am i right in thinking it has only had shell helix semi synthetic in it because thats what subaru use.
i have just changed the fuel filter, spark plugs(ngk 7frb)and panel filter(green)
it has a z4 ecu and sti bb and a centre decat and a green panel filter,and is always run on tesco 99 or shell v power.
i now need to change the oil and filter but am not sure what oil to use.
i was thinking of using some fully synthetic but would i be doing it more harm than good using fully synthetic or should i just carry on using the stuff subaru would use if i took it there.
i know oil is a bit of a sure subject for some but any advice would be appreciated.

 

anyone