I also did some testing at one account with an additive called CGX-4. It won't let me post the URL here but you can just Google it. There were some definite measurable improvements with it. The problem was getting the end-user to pay for it and make sure it got added to either their bulk tank or the truck cylinders on a regular basis. In the end, it was just too difficult to pull off. People have a mind set of doing something a certain way for years and they don't always like anything changing that.