Question

spark plug cooling is affected by spark plug:

a. reach.

b. torque.

c. gap.

d. size.

Explanation:

Spark plug reach (the length of the threaded portion) affects how much heat is transferred from the spark plug to the cylinder head, thus impacting cooling. Torque relates to how tightly it's fastened (affecting seal and heat transfer to some extent but less directly on cooling mechanism), gap is for ignition, and size is a general term. Reach is a key factor in heat dissipation and cooling of the spark plug.

Answer:

a. Reach.