Z-Max didn't improve my car
I purchased Z-Max from a television show on Jan. of 2000. Z-Max claimed to improve your cars gas milage and make your car run better. It did no such thing, so I wasted around $50. The only good thing that came out of it was I have free towing. It comes with the package and that is usually more than $50.
Don't buy into Z-Max! It's up to you! Just take care of your car the old fashion way. Service it!