The short answer is , but the why requires a deep dive into how the original Xbox handles data, how modern emulators (Xemu, CXBX Reloaded) read discs, and how you can rescue your physical copy of Forza Motorsport from the landfill of scratched DVDs.
An XISO can often fit onto a standard single-layer DVD (4.7 GB), whereas a full 1:1 ISO dump usually requires a more expensive dual-layer disc. When to Stick with Standard ISO forza motorsport xiso better