Just had a thought, maybe some of you know the answer. I know that B20 (which I've been running for 5-6 mos) has a couple % points lower BTU than #2, but I'm not sure that a (possibly) 2% decrease in BTUs would cause the 50 - 100 degree drops in EGT that I'm seeing.

So, just a thought, but would Bio hold more water than regular diesel, thereby mimicking a bit of 'water injection effect' as a side effect, and as a result causing cooler temps? Hmmm........

 

Bio Diesel has a higher Cetane rating than Dino. That can cause a drop in EGT.

BD may be slightly more hydroscopic than #2 because it is slightly polar, due to the ester bond, and #2 is non polar. As to the water injection effect I just don't know.