Good stuff to use about every 10k miles thru the intake. It helps remove all the carbon buildup thru the intake system, on the valves,combustion chambers, and piston tops from blow-by. No matter how good your car is there is always some oil blow-by in your combustion chamber. Use a vac line from the intake and let it pull the Seafoam into the intake system while the car is running. Use about 1/2 bottle this way making sure to keep the car running but not above 1k rpm. After you have put in the 1/2 bottle turn the engine off and let it sit for about 5 to 10 minutes. Pour the rest in the tank then start it back up. You will smoke the neighborhood up really good for a few minutes but thats a good thing. You can actually see the black dusty particals come out your exhaust. I did this on a 80k mile Dodge truck I had that ran with a bad intake gasket for a few years. It spark knocked like crazy on 87 gas due to the build up. I changed the gasket and started the seafoam treatment and the knock went away totally after the 2nd treatment. When I finally decided to do a top end rebuild at 120k miles the valves, combustion chambers, and piston tops looke great with almost 0 build-up.This made me keep using it, I have tore into cars with less than 30k miles that looked alot worse. I now use it in my supercharged 05 GT every 10k miles just to be safe. Carbon build-up is a big cause of detonation and in a boosted car that means a quick death to the engine. I would rather be safe than sorry and for $7 bucks every 10k miles the insurance is well worth it.