Mercedes: Diesel Fuel, 1985 mercedes 300d, best fuel additives

Question
I just bought a 1985 Mercedes 300d that was parked for 3 years.  Although it starts and runs good, I was told by the previous owner that the diesel fuel that is in it whas been in it for three years.  It is almost full.  I have been told I should drain the fuel and change the filters and install new fuel.  Should I simply drain it thriough the drain plugh on the bottom or will I need to trake the tank off and do more than simply drain, install new filters and new fuel. Also, should I use some kind of fuel addetive, if so before or after draining the fuel.  Please help I just don't know what to do.  Thank You

Answer
Billy,
Just drain the fuel, not necessary to remove the tank. Purchase some fuel additive from a truck stop. Biodiesel is one of the best fuel additives, as it will strip out the sulfur etc from the tank.
It is often sold for 20+ a gallon as a fuel additive.
If you can locate a biodiesel station just add a quart then top off with the regular fuel. If the bio is unavailable, just ask a trucker what they recommend for cleaning the tank.
Open the water separator clean and change the filter. You should purchase a couple of extra filters, as you will need to replace them as the fuel tank cleaner cleans the wall of the tank.
I would not dispense with the old fuel, just add it back a gallon at a time withe each refill. You will be saving the expense and helping the environment too.
Good luck. Let us know how things turn out.