[Ripplinger]

When I convert old books I've scanned and then converting the epub to mobi, I've been setting the conversion to "old" for the mobi type. There was one book that was 2x the file size when I used the "both" setting, it jumped from an epub size of 365kb to 537kb for "old" mobi format which is normal, but to over 1000kb when I selected "both" as the conversion option.

But now I was wondering if that "old" format type is compatible with newer Kindle readers. I don't want to be restrictive in what readers can view books after I've gone to all the trouble of scanning and editing.

Is setting the mobi type to "old" ok? Or would it be better to set it to "both" regardless of the file size it turns out? Or maybe a different program for the conversion for those odd books that seem to jump oddly in size, it doesn't happen on all books.