ok I know how the smoke color works. The more white the more unburnt fuel. I have a 1993 250 dually CTD bone stock and about 175k on her. Ok I just bought the truck this summer and it of course needed some tlc but she usually blew black smoke under load. After sending her a couple of times for long workorders nothin serious I notice she doesn't blow black smoke under load. At start up she blows a good puff of white smoke. When she's warmed up and running she will blow blewish white smoke harldy any black smoke anymore. Didn't really notice a power lost but just a lil worried. Should I be on the look out for something?

 

Check the downpipe for oil.