All I can say is wow. Their wasn't a lot of smoke that came out, but it runs like a brand new truck. It has had a real rough idle lately and it felt really sluggish when accelerating. It almost seemed like all the power was gone. I had been looking at seafoam for a few months and I figured I would just take a leap and do it. I bought 2 cans yesterday and done it today. I put 3/4's of a can in the brake booster vacuum line. Then the rest of that can in the oil and I put 1/2 of the other can in the Gas tank. It runs so much better. Im going to leave it in the oil until next week when I change the oil.