I read an article a while back and some additives were even worse than no additives at all. however i do remember that stanadyn was number 2 just behind one that was so expensive it was pointless. Get stanadyn it works wonders my truck idels smoother gets about 1-2 more mpg and it even seems to have just a little more go maybe due to the cetane boost. prevents jelling lubes cleans all that.