core/homeassistant/components/tankerkoenig/icons.json

{
  "entity": {
    "sensor": {
      "e5": {
        "default": "mdi:gas-station"
      },
      "e10": {
        "default": "mdi:gas-station"
      },
      "diesel": {
        "default": "mdi:gas-station"
      }
    }
  }
}