[MetroMPG]

It's almost a given that there will be a benefit, but the improvement will be small enough that it may not show up above the usual variability in tank-to-tank results. (If you're planning to do some kind of as-controlled-as-possible test, that's another story.)

So... be wary of using that yard stick. Many modifications on this site are known to work, but they make a very small individual improvement. You'd end up dismissing things that collectively would make a meaninful & measurable improvement.