At this time temperature is not the issue that I am concerned with. My concern is fuel line material on a 1999. I have been running several tanks of B20 in my 1985 300D which has required some fuel line changes that I was expecting. I just want to confirm fuel line material compatibility with biodiesel on a 1999. When the warmer temperatures get here I want to run B100. There is a biodiesel plant underway in Defiance, OH that will be in production in a few months.