I just finished off the bottle of quicksilver that came with the boat I bought the guy I bought it from swears buy it and he has never used anything else, I have always used Johnson/Evinrude mixing oil in the little 1964 6hp Evinrude that I have and it runs great after this long. Is one as good as the other and since I am out of quicksilver but still have nearly a gallon of the johnson left can I use it and mix it in with the other already in the tank. Also what is seafoam and what is it used for and should I use stabil in every tank as well or just add it to what may be the last tank for a while.

Any MAJOR brand of TCWIII oil will work just fine as long as you are premixing. You just don't want that stuff that has been setting in the sun at some convienence store. As fas as the seafoam,,,,it is a carb, cleaner, decarbonizer, mobile-mechanic-in-a-can. Use it two times a year, should be plenty, But use Marine Stabil in every tank of fuel.

the marine stabil is the green stuff!!!!

+1000

Is there a sythetic two stroke oil and is it better. It is time for me to get another gallon soon. I have been using quicksiler plus..

Be careful when mixing. Check to make sure that you aren't mixing a synthetic blend with a straight ash based oil. It should say on the bottle whether or not it's a synthetic blend. If you're premixing then you probably won't have a problem with any TCWIII oil.

MAJOR BRAND being the important thing like Mike said.