I have a 2004 Mercedes 220 which has a fuel tank with a capacity of about 85 litres (it's supposd to run on diesel). Due to someone frigging around at the station yesterday (not me), that fuel tank now has about 76 litres of diesel in it and about 9 litres of regular unleaded. I understand that the diesel fuel is heavier and should remain on the bottom whilst the regular unleaded is lighter and will float to the top. The out-take thingy is near the bottom of the tank and in theory will always draw the fuel at the bottom of the tank, ie, the diesel. As a matter of habit, I almost always keep at least half a tank of fuel in the car and I suppose that means that the regular unleaded will always stay at the top and never get used.
As I don't want to drive to a Mercedes dealership and pay full whack for a perhaps unnecessary draining of the tank, I am wondering my best course of action here. Should I let the tank go close to empty in the hope that the regular unleaded is diluted enough and won't make a problem or should I just always keep the tank at least half full and therefore never get to the regular unleaded anyway as it will always stay at the top of the tank? Any other suggestions? (it's a company car and I don't want them thinking I'm any more of a prat that they presently think I am!!!). Thanks all in advance.