We established lengthy baseline diesel performance MPG on on three Mack 400's. One Sand Carrier (shown below) and two bulk carriers. Fuel Charger Power Cells were installed and MPG was tracked for one to seven months. 
The improvement in diesel performance was remarkable.  

MPG on all three Mack 300 trucks improved from 2.8% to 6.2%. Based on 100,000 average annual miles per Mack, we estimated a total savings 2,450 gallons per year, or about $2,800 annually, at the then current price of $1.15/gallon. At $3.85 per gallon, the three trucks could save a little over $9,400 per year. Quite an improvement in diesel performance!

DIESEL ENGINE MPG TEST