They told me the same thing except aaron made it sound like the mixture was closer to 25%,I switched to amsoil this year and have been using the lucas added to it too and so far haven't came close to burning the gears up the way I used to with royal purple. Max machine worx claims they have tried every kind of gear oil looking for the most gear life/drive life,they even used to sell the alysin stuff and some other exotic stuff,now they say don't waste your money,the best stuff they have seen is amsoil mixed with lucas. I believe them because they are not trying to sell the oil,just sharing what Ive been told and tried,Smitty