Just finished my first tank after adding Ethos FR. I added 3 oz into the crankcase and 2 oz to ~ 5 gallons of fuel. This tank worked out to 66.40 MPG.
Since my LRR tire swap I have been through six 5 gallon tanks of fuel. The highest was 67.15 MPG and the lowest was 64.36. The average over 1999.8 miles was 65.61 MPG.
So the 66.4 MPG tank using Ethos FR falls within that range but is just above the average. The temps were warmer for this tank compared to any of the previous 5 tanks so that might explain the slight increase. Certainly there is not a 7 - 19% improvement. I will continue until I use the whole bottle to see if anything develops.
I'm not sure that anyone else got it, darin doesn't drive enough to test it independently (or as much as possible) of weather and Rick seems to have fallen off the face of the earth (prolly work related).