I use a Bio-Pro 190 http://www.springboardbiodiesel.com/biopro190/biopro190 since 2008 and make fuel for all of my diesels and home/shop oil furnaces. I have over 500,000 miles on our 2005 Sprinter, 2007 Cummins, and 2006 Duramax. My Kubota runs fine on it as well.
I haven't tried it in the Promaster and with fuel so cheap I'm not going to.
Bio-diesel is not the same as just running waste veggie oil.