I am seriously thinking about replacing my 1985 BMW 535i with a 1984 300TD. I like the BMW, but I really miss driving a diesel, and I have always wanted the wagon. Am I nuts? There is nothing wrong with the 535i, and I get about 24mpg (it is a 5 speed). Other than slightly better mileage, which may be offset by the higher diesel prices, what are the advantages of the diesel?