Differences in fill levels occurred after the manual switched between metric and standard, when measuring from the fill hole. So it's just a rounding difference. Most ST will probably never have their fluids touched, aren't driven hard and will probably never experience an issue. Since there are some that are driven hard and have had issues, it is better to air on the side of caution and use the higher fill spec. It's just fluid sitting in the case that gets sloshed around by the gearing and movement of the vehicle. There's no pump and is not under any pressure. There's no risk in going with the higher fill spec. I've used the full synthetic Castrol brand fluid. In placing the hole where they did, it's apparent the engineers made it impossible to truly overfill.