Had this done on my J series motor. A lot of mechanics recommended it too me. My J series had over 200k on it when it was done (TB was also cleaned). I didn't notice any difference in performance, but the smoke that came out the exhaust did go from darker to whiter (it will give off a lot of exhaust smoke the 1st run after it's done). Still have my J series & it still runs strong. I can't say if the seafoam helped, but it didn't hurt.

BTW- I received the service as a gift so I wasn't at a loss for any $.

If it's well maintained, you don't need it. If it hasn't been well maintained, no miracle in a bottle will bring it back to life. Don't mess with it.

Stop screwing around with your car more.

"runs very strong" Why screw with it?

I have a 1995 Honda civic ex with 205,xxx miles on the stock d16. It has been routinely maintenance and runs very strong. I have been searching or things to make it last and work more efficiently and came across seafoam. the stuff that goes into your break booster and loosens up the carbon deposits. please don't answer this if you haven't had any experience with the product or don't know what it is, as I am new to this too. I have done some research and read that if a car has high mileage the carbon deposits could actually be keeping compression up and stopping leaks. Will my car benefit from a seafoam application?