4 ms·Hint: you can fit more if you melt them.by dmoney 16y agoHint: you can fit more if you melt them.quickpost 16y agoBut then they are no longer ping pong balls... Just plastic goop.TeHCrAzY 16y agoThey never said the ping pong balls had to stay as ping pong balls. I'd be thinking about filling the tires with liquid ping pong balls too, but maybe I'd be missing the spirit of the question...