@Connavar: It doesn't, I've checked multiple times. If you install WipEout the
way I told, then the game takes about 187x megabytes. Once you start it up,
while being connected to the PSN, the background download starts. When done,
WipEout takes about 191x megabytes.

I would test it out myself, but my primary disc has about 400GB left and the
largest partition on my external disc is only about 300GB. So it would takes
some time to get it done.

As an additional note to my previous post; just in case you have about one or two
gigabytes left, then you might also download something from the store (instead
of creating a mpeg file) that fills up you disc.