just used this in a friends SiR EK4 when i was servicing it for him and yet again it really surprised me the difference just the gearbox oil alone makes
i would highly recommend that everyone change there gear oil regularly
Ichishima himself states that gearbox oil should be changed along with engine oil on cars that see regular abuse on track or fast road
as if your going to change your oil that gets constantly cooled and filtered then why not your gearbox oil that reaches high temps and isn't filtered