Question

spark plugs are identified by three different features: thread size or diameter, reach or length of the thread, and heat range or ______.

a. plated metal shell

b. internal resistor

c. operating temperature

d. center electrode

Explanation:

Spark plug heat range is related to its operating temperature. The heat range indicates how well the spark plug can dissipate heat, which is essentially about its operating temperature. A plated metal shell, internal resistor, or center electrode are not what heat range is synonymous with.

Answer:

c. Operating temperature