I was hunting through the shed in the weekend when I found an old 4L bottle of Castrol Syntrax 75W-90 with about 1.5L left in it. I had used in my old 5 speed manual Toyota Levin box at least 6 years ago if not longer. Do you think it's still alright to use? I've got a fresh 1L bottle I acquired I could put with it to add a bit of new. Or should I just bin it?
Thanks
Thanks