Hello- I have a question about fuel additives. I had a recent maintenance at a my local Chevy dealer for my '06 Duramax 6600 and they left a bottle of the Standayne Performance Formula Jr. in the truck. Not sure if it was a hint to use it, or a marketing ploy by the local Stanadyne sales folks. Anyway, how beneficial is it using this stuff? I see on their website that it improves lubricity, keeps fuel fresher etc. Will it improve mileage?

I guess I don't want to start spending money on stuff that I will not benefit from its use.

Thanks in advance for your feedback,
Ed