The LG only burns -R at 8x and 16x, (no 12x). I seriously doubt that the results of burning this media at 16x will be pleasing, so you're stuck with 8x. TY G03 is about the only -R that does well at 16x. MCC (Verbatim) 16x -R will produce a readable disc at 16x, but just barely.
Just be happy that you're getting good quality.