If you add AdBlue to your diesel tank, then it can cause you thousands of dollars worth of damage. If you put AdBlue in your diesel tank and start your vehicle, then it will cause very severe damage to your truck’s or car’s SCR system. AdBlue isn’t a fuel additive or fuel. It is a mix of ionized water and manufactured urea. AdBlue will damage plastics and corrode metals used in the engine and fuel system.