Bosch Spark Plug R10 R-10 R 10 On a weekly basis we are asked what is the replacement Bosch Spark Plug R10 or Bosch Spark Plug R 10 In fact this is the porcelain number. The Spark Plug part number is on the metal part of the body. Please type the part number in the search bar on our header of the website at the top of the page & this will show a result...