Over the last 1683 miles I have been testing the results of using one 9ml. tube of Xado, 4 oz of LC-20 at oil change and 1 oz every 1000 miles and 1 oz of FP-Plus per 10 gallons of gas. The results show a 1.101 mpg increase from the previous test of 1723 miles. I am now starting a test that will consist of about 1500 miles using only Texaco gas, a fuel heater I just installed and an oxygen sensor extender. I need to recheck my compression to see if the Xado increase the compression or not like they claim. Whenever I get the compression checked I will update everyone.
I tried using FP as well about a year ago and I didn't really see any increase in milage. Then again at the time my car only had about 40k miles. It may work better for older vehicles.
The Xado is also advertised to increase FE. The LC-20 is also a top cylinder lubricant and might also increase mileage. I am not endorsing any products I was just posting results in case anyone else wanted to try any of the products. As for the FP-Plus it is also a fuel system cleaner which I always ran fuel injector cleaner every few thousand miles, but this way it is getting a full time treatment.