To increase time between automatic saving as draft, open wp-config.php.
Add this line: define('AUTOSAVE_INTERVAL', 300 ); // seconds
This will autosave only after every 300 seconds (5 minutes) instead of default 60 seconds.
to clarify… a draft is a form of a revision even in regards to a post before its published. an easy way around this is to put WP_POST_REVISIONS to ‘false’ in your wp-config file
define(’WP_POST_REVISIONS’, false);
or
define(‘WP_POST_REVISIONS’, ‘false’);
that will disable revisions, just make sure to save as draft if youre not finished with post and do not want to publish it… hope this helps