What is the purpose of spark plug heat range, and what problems can arise from using an incorrect heat range plug?

What is the purpose of spark plug heat range, and what problems can arise from using an incorrect heat range plug?

• A. Heat range determines how many electrodes the plug has.
• B. Heat range determines how quickly the spark plug dissipates heat; too hot can cause pre-ignition or overheating, too cold can cause fouling and deposits, leading to misfires or poor performance.
• C. Heat range determines thread size in the cylinder head.
• D. Heat range affects only cold-start duration.

Answer: (B)