DONT BUY ZMAX

i have a 85 mustang gt. it has 150000 miles on it. i was looking at this zmax crap and i thought that i would give it a try, it does have a lot of miles on it.anyway when i put zmax in my car it did boost my mpg a little for a shot pd., then it hit the fan. it ended up costing a little over $600. my advise is just dont use it. if your engine is not working right then take it to someone that you trust. dont put in a $40 product and think that eveything will be ok