Huw
Club Member
Safe bet is to stick with a GL5 as per the factory spec in your diff. The oils experience higher shock loading than your gear box (or so I’m lead to believe from what I’ve read) which should be a GL4. As per factory spec. As to brands and mineral v synthetic, that’s a personal choice thing depending on your driving style. Personally if you dont hammer your car around a track, a cheap mineral oil in your diff isn’t going to harm it. I’ve just done a Quaife conversion and they recommend a standard EP90 GL5
