Originally Posted by prometheum
i'm not sure you should run severe gear in your transmission, its a hypoid gear oil which contains extreme pressure additives which are really bad for yellow metals like your synchros
This is really, really, really out of date 'info.' Modern, reasonable-quality GL-5 gear oils all have plenty of metal deactivators to make this a complete non-issue. Besides which, the 5MT in a Subaru contains a hypoid differential which really needs a hypoid gear oil for proper protection.