Split a bottle over the five cylinders. 16oz / 5 = 3.2 oz ( 94mL) per cylinder. I suggest you let it soak overnight. Then push out it the next day, reinstall the plugs and start the engine. Get the car on as level ground as you can that way the Seafoam will flow over the entire piston and all around the rings. Seafoam works good when diluted in air or fuel. This way you are hitting the carbon full strength, it does not take much density to work.
Don't freak when it starts blowing black smoke. The black smoke mean the Seafoam treatment is working. I have had them blow thick black smoke for 30 minutes after this treatment. The black smoke is the carbon blowing off the pistons. Let it idle until it stops blowing black smoke. Then take it out on the highway and run it fast until it does not blow black smoke when you floor it. This is what us old timers referred to as blowing the carbon out.
Floor it from a dead stop and watch the rear view mirror for black smoke to determine if all the loose carbon is blown out.
