well if you are looking to put in an additive I would highly suggest ProLong. I don't run it in mine personally but some friends of mine live by it religiously. It to this day has a VW car running over 400 thousond miles and is only using prolong they ae sending it to him to see how ong it will last and they want to blow it up and it won't.
Redline products aren' to bad but I hven;t heard a while lot about them..I've used the Water weeter by them and that seemed to work..
Hope this might help a little....Ohh yeah you might just be trying to downshift into a gear at to high of an RPM that's why it doesnt want to go in easily. IMO...
