I have a 2015 ML 350. Accidentally filled in diesel , about 6 gallons before realizing the mistake. Probably another 2 gallon gas already in the tank. Got panicked and drove back another mile or so back home. Do I need to take it to the dealership to drain the tank?
Or can I fill it up with gas and hope it get diluted? Please help. I am not really knowledgable with cars, I tried siphon through the side, but the 3.5 ft long hose couldn't reach the gas tank.

I read online it could be done through the hood by connecting to the fuel line or something. Again I am not a car expert.

 

My recommendation is to drain the tank completely. I would under no circumstances drive the vehicle, or even start it. If if has to go to a mechanic, it must be towed.

Long story short, mixing diesel with goas will lower your fuel octane number. If you added 6 gallons of diesel, you need 600 gallons of gas @ 93 octane to get 91 octane rated gasoline.

There are also additives in diesel which will affect a gasoline engine. So the best thing I could recommend is to drain the diesel and run the highest octane you can find where you live for a full tank. And don't start the car under any circumstances until after draining the fuel tank.