JigSaw6992

I'm trying to burn some games for my Wii and I've been told by numerous people to burn at 3x yet, whenever, I try to, it burns at 3.6-4x even though I've set it to 3x. I know it's not the drive because I tried this one both of my other drives and I know it's not the disc because I've tried 3 different DVD brands. What am I doing wrong here?