How to Read Spark Plug Heat Range?

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Spark plug heat range is indicated by numbers, which are typically located in the middle of the model number. For example, in the model BP5ES11, the number 5 represents the heat range of this spark plug. Different brands have varying heat ranges, and each brand's heat range corresponds to specific vehicle models. More details about spark plug heat range are as follows: 1. The heat range of a spark plug essentially refers to an indicator of its heat absorption and dissipation capabilities. Higher-revving engines require spark plugs with higher cooling heat ranges. 2. Heat ranges are categorized into numbers 1 through 9, where 1-3 indicate low heat range, 4-6 medium heat range, and 7-9 high heat range. Most passenger car spark plugs fall within the 5-7 range.