As a RV transporter, I have tried several fuel additives with various results. After using the free trial 3oz bottles that treat 240 gallons...about 3500 miles later, I have opted to buy 10 bottles of the OTR treatment due to the time of year and the colder temps in in my service area. I have seen a increase varying from 1-3 mpg depending on weather/wind, have seen an average of 2mpg gain, both towing and empty, with a smoother-running engine and less smoke.
I have been using Fuel Ox® Infinity Lube™ SG, Liquid Friction Eliminator and Super Spray for almost 10 years now within the wind turbine industry. The results are totally unequaled and the sustainability's light years ahead of all other greases and lubes. All grease we tried before, not only would not present measurable sustainability, but would even cause drag of the energy outputs. The Infinity Lube™ system actually increases the outputs of the turbines.
With Infinity Lube™ we stopped losing bearings, they used less grease, and water was hardly coming out. Failed bearings decreased and our greasing intervals went from 2/day to once or twice a month. Our total savings in bearings alone is $9,645,000 since then. This figure also does not take into account the elimination of the labor costs for replacements, decreased downtime, PLUS reductions in greasing intervals. This gives us an ROI of over 100x.