The most recommended format for PS2 games. It is lossless, meaning no game data is removed, but it significantly reduces the file size. GZIP (.gz):

Yes, but with strict limits. The smallest functional, complete rip of NFSU2 for PS2 is around 700 MB to 1.2 GB . This is often a compressed archive (like a .7z or .rar file) that, once extracted, becomes the full 4.7GB ISO.