DEEZEL, you are basically right, but your points really do not compensate for the fact that a vehicle at slower speeds is under LOAD, and/or cold, and as such is not able to burn all of the fuel being metered into the combustion chamber as efficiently as it should, or would under ideal circumstances. And yes, the turbocharger does help...
Remember that early Porky Pig cartoon when he was strapped to a chair and forced fed pies? Ever notice diesel cars that have soot all over the rear of the vehicle?
The metered fuel is injected directly into the combustion chamber At the top of the compression stroke and just at about TDC. What's in there is either going to completely burn, or not. Depending upon all factors, including outside air temperature. There's no going back (Thomas Wolfe) to the fuel tank after that.
My contention is that a diesel engine that is cold, and/or under load (at slow speed) will not fully burn all of the fuel supplied it efficiently enough to result in a "clean burn" if it is being fueled faster than it can do so. Ever notice how your diesel smokes more under hard acceleration? Hmmmm...
Also the fact is, that no one (not even Mercedes)
has really manufactured a completely compatible automatic transmission for diesel engines. The optimum performance achieved by Rudolph Diesel's invention (1892) is done so only by the proper use of a manual transmission that allows the engine to operate in it's optimun RPM range, or "Power Curve". That's one reason that I follow Bob Bondurant's guidance on manually selecting gears in an automatic transmission.
Try it my way, and see if your results aren't better, your emissions less, and your transmissions and engines don't last longer. I was taught to drive diesels that way, and I never taught anyone to drive differently. Frankly, I went out today, and tried several different ways of driving my Mercedes diesel just for S&G, and I can't imagine how y'all can do it "your way".
Finally, "blowby" really is the amount of combustion gases that pass by the piston rings, so it really can't be accurately measured. Only compression can. As Larry Bible has pointed out numerous times, if your diesel car starts up right away, you got compression.
Ben, I think y'all's got compression, by gawd!