Spark plugs are a vital part of a gasoline-powered car's engine. Without them the engine won't start, and if they're in rough shape the engine will run poorly.

Like every in-vehicle system, spark plug wires eventually break down and need to be replaced as they are used. Experts recommend that spark plug cables should be replaced every 30,000 to 70,000 ...

However, modern-day engines have no distributor, nor coil, nor even spark plug wires, because late model trucks use distributorless coil-on-plug ignition systems. 0:00 / 0:00 ...