Here's What Makes Spark Plug Sockets Different From Standard Deep Sockets

How often you change the spark plugs in your car depends on the recommendations of its manufacturer. Typically, it'll be somewhere around the 100,000-mile mark for new vehicles, but it could be much lower if you own an older car. However, in every case, it's better to swap out the old plugs for new ones before any signs it's time for new spark plugs appear.

Changing the spark plugs on some vehicles is a task better left to professionals, mostly due to access issues that require you to remove various components to reach the plugs. However, on many older cars and trucks, as well as on many newer models, swapping spark plugs is a moderate DIY task — as long as you have the right tools, that is.

In addition to a quality ratchet and a few extensions of various lengths, you'll likely need a spark plug socket of the correct size to remove your old spark plugs and install the new ones. If your socket set doesn't include a specialized spark plug socket, you may be tempted to use a standard deep socket instead. However, there are a few design features that make spark plug sockets the right tools for the job, including a built-in magnet or rubber grip that helps you avoid dropping plugs down the spark plug tubes. 

A quality spark plug socket will have an interior rubber insert designed to protect the spark plug's fragile body and hold it tight while removing it from the engine. Some also include a magnet inside to maintain a better grip on any spark plug inserted, as well as thin walls to fit into spark plug tubes or a rough outer surface to prevent slippage when the tool using with oily hands. For example, Harbor Freight's $9.99 Pittsburgh ⅜ in. Drive SAE and Metric Spark Plug Socket Set includes five sockets, each with a rubber insert to protect the plug and help assist with removal and installation.

While replacing spark plugs isn't necessarily a wrenching skill everyone should learn, it comes in handy when performing maintenance on everything from passenger cars and trucks to dirt bikes, string trimmers, and chainsaws. 

The spark plug sockets or wrenches that sometimes come included with a vehicle's maintenance tools are often stamped metal affairs with no protection or grip. In the case of these cheap wrenches, a standard deep socket could be the superior option. However, sometimes, a standard socket won't fit into the recessed area where the spark plug lives, making a thin-walled spark plug socket essential. That said, spark plug (or standard) sockets that lack interior protection can be modified with some rolled up paper or soft foam, such as pipe insulation, to provide more grip and padding in a pinch.