i heard on another forum that ball bearing turbos need one and conventionnal ones don't..
Yeah, I've heard this everywhere. That's why I put one on my GT28R 2 years ago, and a year later the bearings crapped out. And then I put one on my GT28RS, and a year later the bearings crapped out on it. From what I keep hearing, most folks don't need one with the Protege, due to the lower oil pressure.