Use This Spark Plug Size Chart when changing your spark plugs!

Spark Plug Size Chart

Spark Plug SizeSocket NeededApplication
14mm14mmNewer European and Asian motor vehicles and (some) motorcycles
9/16″9/16″Ford Motor Vehicles
5/8″5/8″Newer motor vehicles e.g (GMC, Subaru, Nissan, Chevy), Small engines eg. (Briggs & Stratton, Koehler)
11/16″11/16″Older BMW Motor Vehicles
18mm18mmSmall Engines (some), Most Motorcycles
3/4″3/4″Lawnmowers, small engines, and older GM vehicles
13/16″13/16″Older large engine vehicles
7/8″7/8″Aviation, tractors, and older vehicles

What are spark plug sockets?

Spark plug sockets are designed to install and remove spark plugs. Spark plugs can be found in many types of engines, from motor vehicles to lawnmowers. A regular socket can damage the insulator of a spark plug if it is not the correct depth. This is why a spark plug socket is highly recommended. Spark plug sockets also assist with holding the spark plug and locating the hole it will thread into.

Spark plug socket types

Spark plugs come in two types, a magnetic type, and a rubber boot type. The magnetic spark plug socket uses a magnet to hold the spark plug inside the socket. A rubber boot type socket uses the rubber piece to grab the spark plug.