Had a buddy of mine recommend this to me its a, Mobil1 API GL-5 synthetic gear lubricant (limited slip)? Anyways I'm about to change the fluid in my 2010 mk6 golf 5mt (2.5L), and when he had recommended this to me right before pulling the trigger, I got a little skeptical.. Was wondering if anyone had some input on this if they have ever actually used it? Pros/cons? Is my buddy an idiot? Lol. Thanks in advance!