I was speaking with my sister last night. She works for Newmont Mine Company in Northeastern Nevada. She's an underground geologist with the Gold Mining Group. They run 70 series diesels in the mines. She said the 70 series diesels were all recenlty pulled from underground because, after mutiple attempts, they couldn't get the DPM low enough. DPM= Diesel Particulant Matter. I suggested they try to run Bio, but Neumont isn't setup to make Bio-D. Any suggestions to lower DPM?