After reading many threads on here it seams that the most popular rear diff oil is castrol syntrax, so as my car (uk my99 turbo) is due for it's diff oil to be changed I have bought a ltr. before fitting it I phoned my local subaru dealership to check what they fit (call me paranoid) they said they only fit mobil 80w90 LS oil.
I am now worried that the syntrax is not LS spec and will do some damage to the diff, is this the case ?
thanks, Mike.

 

A 99 UK turbo does not require a lsd oil as it has a viscous rear diff. Syntrax is fine
A P1 however would, and most STI or RA types

 

does that mean that all the uk turbo cars that have their rear diff oil changed at the dealership have had the wrong oil fitted ?
and will the ls oil damage their diffs ?