Don't know if there are issues with a 6.0 and bio. It's the 07 and newer that need modification. As far as additives, I ran 30% bio without problems most of last winter, even sub-zero. Running 50/50 now, but hasn't gotten below the 20's until today. Think I did have a shot of Diesel Klean in it when it was 17 below last year??? Anyway, even mixing you will save bucks, My last few batches were $1.08, $.93, $1.30, $.68, and $.98/gal to make.