If You have an original copy of a game eg. wii sports insert it in to the LG Dvd Drive And Use Raw dumper there is a guide on how to copy original wii games here
Tystan I have the same DVD writer (Pioneer DVR-111D 1.29 firmware) and what you experience is the minimum write speed. Yes it's x4. Don't worry about it, the speed is not what distinguish a bad CD from a good one. Good writer + good media = burning at optimal speed!
Example can be shown here what I've done with MCC 03RG20 (Verbatim DVD-R x16) using ImageBurn at various speeds:
This is burning Wii Sport Resort ISO at x4
This is burning Wii Sport Resort ISO at x8
This is burning Wii Sport Resort ISO at x12
Conclusion! On my computer with my batch of MCC 03RG20 with my Pioneer DVR-111D I get the lowest PIE and PIF using write speed of x8. Now I can use the remaining 47 DVD's at that speed having best quality. Should I swap to my best DVD's I will consider higher speed.