have a 2000Ford F350 diesel and mistakenly put 3 to 5 gallons of gas in it then filled it with diesel fuel some one said to add 2 qts of automatic tans fluid and it would help or should I drain the tank
2-3 gallons of gas in how much diesel?
Assuming a large tank and assuming the rest of the tank is now full of diesel, you should be OK. In the old days we added a gallon during the winter to prevent clouding.
There is a possibility that some of the fuel system may not be able to stand up to gasoline, but I suspect your truck will be OK. A potential big problem is damage to a pump or injector due to too little lubrication. That is what the suggestion for the oil was all about. I doubt if it (the suggested oil) would hurt other than a possible bit of smoke.
However 2-3 gallons in a almost empty tank, that would be bad to drive with.
a 28 gallon tank
If you only have 2-3 gallons of gas mixed with diesel in a full 28 gallon tank, I think you will be OK. I would probably refill it with diesel when it gets half empty, or so, just to dilute it some more.
so the advice is I don’t need to drain the tank?
are you sure
That is what I would do. I once accidently put about a gallon of gasoline in my 21 gallon diesel tank without any noticeable effect. If you really want to be sure for your engine, give your ford dealer service department a call and see what they say. I suspect it will not be the first time they’ve been asked that question.