Not to be argumentative, but....black smoke from a diesel is a sign of to much fuel for given load and engine speed. Which will cause egts to climb fast and hot and could cause engine damage... i.e. melting the turbo and pistons.....when a diesel is properly tuned it will create a haze of smoke till the turbo gets spooled. And with the correct ratio of fuel to air will make the engine most efficient and reliable. A well tuned engine will make just as much if not more power then one that is clouding the atmosphere. Granted I know it's not as dramatic as seeing a plum of smoke but it's efficient.