The ACDelco heat range chart is a chart that provides the ACDelco spark plugs’ heat rating in addition to other attributes. The heat rating reflects the spark plug’s thermal characteristics, or how hot or cold the spark plug is.
The graphic outlines the identification table for plugs. It includes possible spark plug prefix, suffix, and numbering options. The numbering part includes thread size and temperature range. In addition to the temperature rating and thread size, the chart also includes the construction shape, taper seat kinds, projected gap types, and plug type. In addition, the chart describes the resistor, the spark gap, and other design elements.
The heat rating number indicates whether the spark plug is prone to overheating or has the ability to withstand overheating. The heat rating varies from 2 to 12, with 2 being the hottest and 12 being the coolest.
A spark plug with a low heat range or high heat range features a long, thin insulator nose that heats up fast but does not transfer heat to the metal shell readily. In contrast, a high heat range or cold spark plug has a short, thick insulator nose that rapidly dissipates heat.