Yes, this is a elementary question, but I am looking for a concise answer from you Pros.
My '85 300D smokes when I nail it and when I am running down the highway under a load. It is not super excessive, but noticeable. I am wondering if the pump timing is off or something else. All maintenance is up to date and the car runs well, but I also only achieve 23-25 mpg, while others achieve 27 mpg regularly. Any and all ideas are welcome
Thanks.

'85 300DTurbo-175,000 miles