Hi all and happy holidays. I have read all the posts concerning my make and model and have gained a tremendous amount of knowledge through this great resource. One thing that puzzles me is all the remarks about exhaust smoke. I don't know if I am just lucky but my 300D never spews any smoke upon start-up or running. The only time I can see anything remotely resembling smoke is when I really get on it at night and look at the headlights of the guy behind me. It is just about invisible during the day. I have adjusted the ADLA to Kent's specs which would account for this slightly dark hue in the wake behind me, but I would hardly consider it "smoke". The car has 160,000 miles on it. I am pretty sure the injectors are the originals, the timing chain is tight and the valves have been adjusted. I live in the Boston area and this gem starts in single digit and sub-zero weather without even being plugged in. I have never checked the compression but I would have to say it is good. I change the oil religiously every 3000 miles.( Rotella 5w-40 synthetic, forgive me Kent but the conventional oil I can't find in 5w-40 and with the cold weather...well you know.) I use Diesel Kleen cetane booster as an additive with every fill-up and I have just ordered the Diesel Purge from this site which I am dying to try. I really can't see this car running any better but I have heard so much about this product I figured it can't hurt. I only burn diesel, no veggie or bio. Are all these smokers I read about due to alternative fuels, mechanics, maintainence or a lack of?