I am wanting to try the stanadyne fuel additive but i went to there web site to find a dealer and noticed that there was alot of differant types of additives. Which one does everyone use in their duramax.

Most people use the performance formula, including myself. It includes everything you would want, including plenty of the lubricant. It doesn't have as much as the "lubricity" formula has, but I believe it's more than enough.

I also use the performance formula.

I use the performance formula.

Lucas Oil, fuel and oil treatment here

I use Stanadyne Perormance Jr. What's the difference between that and the Stanadyne Perormance? Is one better?

I have used he Performance formula and when I ran out, I switched to the new stuff from Amsoil, which I like very much. I can buy the cetane booster and the basic additive separately and then in winter, I can add the cold flow improver later instead of year round like the Stanadyne is already mixed.

I love them both, but I just prefer the amsoil for my situation.

I also use the performance formula.
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I also use the performance formula and have not had any problems yet.