I read in a previous post
http://forum.gopowerhungry.com/2004-...-program.html? that if you are running an octane level other than the one specified for a tune you should retard/advance timing. Im kind of clear on it but just want to be sure. Im running 87t canned tune but always run 93 octane. BTW its a 06 5.4 if it makes a difference