I don't know the reason for the difference in smoke exactly but i would assume the CR smoke less because in has several pulses of fuel rather than one big one. I think the older diesels have one big pulse and thats the reason for the noise they create compared to newer CR's. I could be wrong, at the automotive schools I went to we never really talked much about diesels nor saw them. I wish I spent my 30 grand on a diesel school over a expensive automotive school, I might know the difference. I became a convert from gasoline to diesels too late to pay much attention to the 12V and 24V.
I have often thought about what the EPA thinks about us turning up our diesels. I guess they are slowly catching on and slowly reacting to us making them smoke. That probably why they started requiring DPF's (diesel partical filters) oh well all someone has to do is probably alittle fab work and removing the DPF, then have a ECM made without the new Emissions bullcrap involving DPF and such, that way you could take your truck to get inspected and pass since now check engina lights. sound simple but can't be done over night or with just pocket change.
Really I think the epa is going about the whole pollution and global warming thing all wrong. IF WE CAN MAKE PURE OXYGEN FOR PEOPLE TO CONSUME AT SOME CLUBS AND IN HOSPITALS, WOULD IT TAKE THAT MUCH WORK TO MAKE ONE OF THOSE OXYGEN GENERATORS ON A LARGER SCALE? I MEAN SERIOUSLY IT SHOULDN'T BE THAT HARD THEN THE FEDERAL GOVERNMENT CAN REQUIRE A CERTAIN OXYGEN OUTPUT FOR A CERTIAN POPULATION LEVEL PER COUNTY IN THE USA. WE CAN'T FIX WHAT WE HAVE DONE BY SLOWLY DONE ON OUR POLLUTION WE CAN ONLY FIX THE POLLUTION BY REVERSE ENGINEERING IT INTO SOMETHING BETTER. HECK WHY DOESN'T THE EPA REQUIRE AUTO MANUFACTURERS TO MAKE A OXYGEN GENERATOR ON A SMALL SCALE TO PUT ON EVERY VEHICLE MANUFACTURED FOR SALE IN THE USA. IT CAN BE MADE POSSIBLE AND REALLY THEY CAN MAKE IT SO THAT IF THE SYSTEM ISN'T WORKING FOR 500 MILES THEN THE PCM SHUTS DOWN THE VEHICLE. I am not shouting I am just making it more attention grabbing. I don't mean to steal anyones post I just felt you were talking about emissions and felt it was ok to talk about them too. after the epa is the reason why are trucks don't smoke as bad.