Where to Check the Heat Range of a Spark Plug?

[IsabelaFitz]

Spark plug heat range can be identified in the middle of the model number. The heat range of a spark plug is represented by a number, which is usually located in the middle of the model number. For example, if the model number is BP5ES, the number 5 indicates the heat range of this spark plug. Different brands have different heat ranges, and each brand's heat range corresponds to specific vehicle models. The heat range of a spark plug refers to an indicator of its heat absorption and dissipation capabilities. Higher-revving engines require spark plugs with higher cooling heat ranges. The heat range is represented by numbers from 1 to 9, where 1-3 indicates a low heat range, 4-6 a medium heat range, and 7-9 a high heat range. Most passenger car spark plugs have heat ranges between 5 and 7.