(1) what is the major reason people deleted any part of the diesel emission system? Most, but maybe not all, whine about cost.a small fraction do it for performance and some do it because they like to customize. For the second group, fine, but the it becomes a race vehicle which shouldn’t be allowed registration and a plate. I run VP 110 leader in my race cars and they aren’t regular drivers. For the third group, deleting is just selfish behavior.

(2) assumption, yes I assumed most delete out of frustration due to the continued expense of maintaining the emissions system function per original design and state/federal emissions laws.

(3) if you monitor EGR as you drive you’ll see it’s actually fairly active.

(4) I completely believe emissions controls lower the efficient and performance of all types of internal combustion engines. No argument from me here. It’s the societal price we pay to have millions of cars on the road burning billions of gallons of fuel each year.

(5) of you want to drive a vehicle longer than the life of its emissions system components, which is a completely discretionary choice, then I think you should pony up and fix the stuff. I have to keep my dog’s vaccinations up to date no matter how old she is, so why is it you don’t have to keep up your emissions control system in your car? Now, in the USA (excl a few states like Calif), if you Car is old enough you don’t have to retain any emissions gear. I’m ok with that as I applies to collector vehicles that aren’t used more than a few thousand miles a year. In particular, emissions controls from the 1970’s worked poorly and really cause operating and longevity problems. CAT’s, however were a good invention and I applaud hot toddlers who put high flow cars on their street machines.

(6) no argument from me on the pro’s of diesel over gas. I picked an X5 d over the 5 liter gas model for the economy and torque. Had i a chance to do it over maybe I would have gotten the V8 as the lower repair costs may have offset the higher fuel consumption.

I guess my point is we all live in a society/earth where we have an obligation to not trash the place for everyone else. However, There will always be those who disagree and feel the entire plant is theirs and theirs alone for the trashing. I have acquaintances like that. These are the guys that dump their used automotive fluids and solvents out back, and toss cigarette butts on the ground because “they are trash,” or “it’s a free country,” or “why should I dirty up my ash tray?” And for these wonderful people, we have laws and enforcement of those laws is ok by me.