It seems like Turn 10's upcoming racer is a huge title, and you can now prepare by pre-loading it.
Forza Motorsport for Xbox Series X will run in 4K at 60 fps, have ray tracing - CNET
Forza Motorsport Is Now Available for Pre-Load With a Huge File Size - IGN
Forza Motorsport PC & Xbox download size
Buy Forza Motorsport (PC / Xbox Series X
Why is forza 100gb just like pc and series x? : r/XboxSeriesS
How much space does Forza Horizon 4 and 5 take up on PC? : r/forza
Preloading has begun for Forza Motorsport (132.09GB) : r/XboxSeriesX
How much space does Forza Horizon 4 and 5 take up on PC? : r/forza
Forza Horizon 5: requires 103GB storage on PC and Xbox Series X/S