Due to differences in design and materials the plugs listed in cross reference section are not exactly alike.
New Ac Delco Spark Plug Heat Range Chart
Pictures. Looks like all spark plug manufacturers does not follow the same convention. Spark plug heat range is the measure of how fast the spark plug tip dissipates combustion heat.
Spark Plug Cross Reference HEAT RANGE CHART from www.briskusa.com
I am getting mixed answers from the internet. In these instances, a colder plug may be needed. Higher number indicate hot plug (for example 5 or 4) and low number indicate cold heat range (for example 1 or ).
Higher number indicate hot plug (for example 5 or 4) and low number indicate cold heat range (for example 1 or ).
2544 is the coldest plug in that plug family, and 2546 is the hotest. The heat range numbering system used by spark plug manufacturers is not universal. 3.part number 276s may be used for header applications in place of p/n 276. Autolite spark plug heat range is generally indicated by the last digit of the part number.
