A healthy ignition system is absolutely critical to the smooth and reliable operation of your car. Whether you drive an old classic with a distributor or a modern system with ignition coils, it is very important to maintain your ignition system to make sure it is working at its best. With the many advances in technology over the last few decades, there are a wide range of different types and styles of ignition systems. However, the spark plug is one component that has remained present in almost all modern ignition systems for gasoline powered cars.
To achieve optimal spark plug performance, you must set the gap prior to installation (4 prong spark plugs as well as some high quality 2 prong typically come with the gap already set). By definition, the gap is the distance between the electrodes. If the gap is set too wide, the spark plug may have difficulty firing. If the gap is too small, the spark will be weak and the plug will be prone to fouling. To set the gap, there are a few different options as far as tools go. While there is a myriad of tools that are called “spark plug gap tools” or “spark plug gappers,” the reality is that most of these tools are relatively imprecise and not great at what they are advertised to do. While you can set the gap adequately with them sometimes, they aren’t calibrated so you really don’t have an entirely accurate idea of what you are setting your plug gap to when you use them. So if spark plug gap tools aren’t that great, what do you use?
The Best Spark Plug Gap Tool
The best spark plug gap tool around is actually a set of feeler gauges. Feeler gauges are calibrated so you can accurately set your gap. Furthermore, you can easily differentiate between gauges so you know the exact value you are setting your plug to.
As far as what feeler gauges to get, there really isn’t that much difference between brands. They are all just a collection of metal strips of varying thicknesses and it would be hard to discern major differences in quality even for professional mechanics. That said, there’s no reason to spend a lot of money. They are cheap enough to replace if you lose them or bend them.
In short, the best spark plug gap tool is in fact not a spark plug gap tool at all. Our recommendation is to pick up a good set of feeler gauges for accurate spark plug gapping every time. You can take a look at some of the feeler gauges on the market by clicking here.