I have finally managed to crunch all the numbers for year two’s fuel economy, as well as the two year average. This year, we drove our Suburban 21,498 miles (as of June 30, 2012). The Suburban consumed 888.972 gallons of diesel fuel, for an average of 24.183 MPG for year two. Over the life of the conversion, we have driven 39,983 miles, consumed 1629.830 Gallons of fuel, for a two year average of 24.532 MPG. I have also figured out that if we drove it just as far, but it was gas, getting about 16 MPG average, then we would have used 2499 gallons of gas. At $3.459 per gallon, we would have spent $8644.05 on gas. Instead, we burned 1629 gallons of diesel, at 3.909 per gallon, we spent $6367.76 on diesel fuel, for a total savings of $2276.29, which is nearly the entire cost of the Suburban (which I bought with a bad engine and trans) plus the diesel conversion. A fresh gas engine and trans wouldn’t have been much cheaper, so I think I made out pretty good!