Why can't I download a game from PSN?

My PS3 says I have 18g available and the game is only 11g. Is that cutting it too close where there's a fail safe or something? It's an older 80g

Glimmer Man2013-11-05T07:56:30Z

Favorite Answer

From my experience you need at least twice the required space available. It will take 11GBs to download the game and another 11 to install it. So you would need 22 GBs available to download and install the game. Once you have installed it, you will get 11GBs back to use on your HDD.

Nate2013-11-05T19:35:44Z

if you need more space delete your game data and not your save data.
you will be able to load up your save data, you will just have to install game data each time.
new PS3 models are becoming cheaper