Help with Updates

[Swift20B]

To start, I own an old 40 GB PS3. The system says it has 37 GB Free.
Well, my CD copy of GT6 has gone bad. So I reformatted my HDD and downloaded the digital version. (The size of the game is the same, 15 GB).
Yet, when I go to update the game. It first told me I needed 37 MB free to update. I restarted my system and now it says I need 65 MB free to update.
I don't know what I'm doing wrong as my HDD is completely clean except for GT6.

Does anyone else know how to fix this?

 

[Swift20B]

Found the issue. My 40 GB (37 irl) is at 32 GB after the HDD had been formatted (5 GB for OS). I found out that GT6 including all updates comes in at a heavy 32 to 33 GB. So, my HDD is too small. Now the plan is to get another HDD or buy a PS4.