Hi Hows things? Just seeing if anyone can give me advice on Diff oil for a P38. Have purchased Penrite Outback Hardened Diff/Gear oil 80W-90 only to find out that it may not be suitable. It is API GL-5/GL-6 but on Supercheap website it states that it is not compatiblewith the p38. Any help would be greatly appreciated. Cheers