If you want to find out whether suExec is running on your hosting account, create a .php file in your web account with the following in it:
PHP Code:
<?php phpinfo();
Load that page in your browser. If you scroll down about 1/4 of the length of the page and there is a section called apache2handler. In the bottom row of that table is the loaded modules. If mod_suexec is not listed, you are not running under suExec.
If it is listed that does not guarantee that it's running on your account, but in a shared environment, I would guess the probability is pretty high that it's being used. To further test you can set the permissions to 640 on
wp-admin/index.php. If you can still load the dashboard of your site, then you probably will be ok to proceed with changing the permissions on your
wp-config.php. Do test after you change them though ;-)