Five used spark plugs on a wooden bench, some clean and some hea…

Close-up of five used spark plugs laid out on a wooden bench, showing white ceramic insulators and NGK-style hex bodies. The plugs vary in condition — some threads and insulator noses are tan and clean while others are heavily crusted with light-colored deposits, and one ground strap is nearly buried in buildup.

AI caption April 2006 · Photo 4267 of 5000