.....ingo, maybe it helps get people's attention if you put a link to the US Govt agency designed to deal with this sort of thing. been "common knowlege" for a while now I thought, but maybe not? http://www.epa.gov/otaq/regs/fuels/diesel/diesel.htm Wylie Bean TheRingmeister at triad.rr.com 90 Cq 99.5 A4 Avant 1.8Tq 01 allroad q 2.7T