i used it in my mustang when i had an old tired 100k plus motor in it before, it had a certain miss right around 2400 rpm, and was a bit sluggish. After a good seafoam treatment it never missed again and felt a little peppier. I used it in my 98 explorer with 200k on it and noticed little or no effect.
BTW, for uses BG induction system cleaner, they crack your throttle body about 1/4 to 1/2 way open and hook up the bottle to a hose that slowly releases the cleaner over a 10 minute period. Had it done on my girlfriends sebring and it definatly helped it.