Spark plug with supply passage for fuel, and a system with same

A spark plug for an internal combustion engine, having the following features:

• a supply passage, a center conductor, an insulator surrounding the center conductor, and a metallic body surrounding the insulator;
• a center electrode connected in an electrically conductive manner to the center conductor and at least one ground electrode connected in an electrically conductive manner to the body form a spark air gap;
• in a region of its front end, the spark plug has an external thread for screwing the spark plug into a component of the internal combustion engine and has at least one discharge opening of the supply passage;
• wherein, at its front end, the spark plug has, attached to the body, a sleeve that contains the external thread,
• the body has, on its outside, at least one groove that forms a section of the supply passage, and
• the sleeve has a heat conducting section that contains at least a part of the external thread and that is in contact with the body and covers at least portions of the groove.