I don't think I've ever seen a situation where that's true. And I've converted a lot of repositories (I maintain the svn2git project). SVN has its metafiles, but git has the full history locally. In all but the most trivially-sized projects, the git clone is bound to be larger. For larger projects it can be several orders of magnitude larger.
I'm aware of that and didn't imply otherwise. But the storage mechanism is for the history, not for the materialized files in the working directory. That's going to be the same for either git or SVN, since they're checked out. So you're talking about comparing git's history DB to SVN's metadata files. The metadata files are effectively constant cost whereas the git history grows with each checkin. They get quite large.
