Some truckers use the oil from an oil change as added fuel in the tank. In this case it will Not ruin your tank
Salt can ruin anything made of metal or steel
Yes
Putting sugar in a gas tank will mean a trip to the garage since the sugar will ruin the gas filter and go into the engine.
it will probably ruin the gas tank and be considered vandalism
Yes, get that thing out of there. It's gonna ruin your engine.
water or coca cola
there isn't one you mix the gas and oil in the gas tank(make sure you have 2 stroke oil).
If you mean you are planning to run a diesel engine on used cooking oil then you will need to change to a compatible fuel filter , and it's worth filtering the oil before filling your tank as well.
it depends if its a older bike you may have to put premix in (mix of oil and gas) in the tank if its a newer bike it will have oil injection and you only have to put oil in the oil tank and it mixes with gas in the carb, in any case try to get a manual for the bike in question it will tell you what to do
it can damage your car. your gas tank is just a tank with gas, it's kind of hard to damage it.
oh ya, lol.
No.Because it could ruin your motor.