Top 5 Best Spark Plug Gap Tools in 2023 Reviews

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No matter what type of car you have, you will want your spark plugs to fit correctly. While you may think you can just screw in any spark plug and forget about it, that’s not always the case.

The spark plug also needs to be appropriately gapped, and this is especially important when it comes to high-performance vehicles but also for your everyday car. This is because if your spark plugs are appropriately gapped, you will have not only better gas mileage, but possibly even more horsepower available to you.

This is where a spark plug gap measuring device comes into play. But, finding the best spark plug gap tool for your needs might not be that straightforward.

In our review, we are going to look at our top 5 favorites, so you know where to start when you go shopping for your next gap measuring device.

Best Spark Plug Gap Tool

Best Spark Plug Gap Tools Reviews

  1. Stainless Steel Feeler Gauge Dual Marked Metric and Imperial Gap Measuring Tool – Best Feeler Gauge Spark Plug Gap Tool
  2. A & E Hand Tools 4450A E-Z Grip Spark Plug Gap Gauge – Best Screwdriver Grip Spark Plug Gap Tool
  3. Lisle 67870 Spark Plug Gauge Gap – Best Ramp Style Spark Plug Gap Tool
  4. Performance Tool W163C Wide Gap Wire Spark Plug and Gauge Tool – Best Wire Loop Spark Plug Gap Tool
  5. Stanley Proto J000K Spark Plug Gap Ga Set – Most Lightweight Spark Plug Gap Tool

1 Stainless Steel Feeler Gauge Dual Marked Metric and Imperial Gap Measuring Tool – Best Feeler Gauge Spark Plug Gap Tool

Starting off this spark plug gap tool roundup is an offering from the Hotop Store. This is a feeler gauge type of gap tool.

It features a pocketknife type case that includes 32 blades made from manganese steel. Each one of the 32 blades has a different thickness. And as you move from one blade to the next, you will notice numbers etched into them. These numbers will provide you not only a metric measurement but an imperial one as well.

So many sizes…

Starting with the thinnest blade, you will notice a metric size of .04mm or .0015 inches. From one module to the next, they will increase in small intervals all the way to 0.88mm or 0.35 inches in thickness.

All of the different blades are held in place by a central locknut. So, you can quickly move from blade to blade with hardly any effort at all.

Easy reference…

You will also notice that a couple of the blades are in a different color than the rest. This just helps give you a reference point when going from one blade to another.

Stainless Steel Feeler Gauge Dual Marked Metric and Imperial Gap Measuring Tool
Our rating:5 out of 5 stars (5 / 5)


  • Covers multiple spark plug gaps.
  • Minimal error of measurement.
  • Don’t take up much room when folded.


  • Material is not rust-proof.

2 A & E Hand Tools 4450A E-Z Grip Spark Plug Gap Gauge – Best Screwdriver Grip Spark Plug Gap Tool

The A & E Hand Tools spark plug gap tool is about the size of a small screwdriver. It features a little pocket clip so you can easily carry it with you, which we like.

As you hold this tool in your hand, you will notice imperial measurements on one side and metric on the other. This plug gap gauge offers metric measurements ranging from as little as 0.6 to 2.0mm. The imperial sizes go from 0.020 to 0.080 inches.

That’s not all…

Located on the tip of this tool is a small rectangular hole, which you can fit your spark plugs ground electrode through. This will enable you to increase or decrease the gap between the electrodes quickly. You will want to be careful while doing this, though.

While the metal parts of the gauge are plenty durable, the plastic handle isn’t. Just make sure to take your time when applying pressure, or you may crack the handle.

A & E Hand Tools 4450A E-Z Grip Spark Plug Gap Gauge
Our rating:4.6 out of 5 stars (4.6 / 5)


  • Handy pocket clip.
  • Metric and imperial measurements.
  • Easily adjusts the electrode gap.


  • The plastic handle could be more robust.

3 Lisle 67870 Spark Plug Gauge Gap – Best Ramp Style Spark Plug Gap Tool

Lisle has made this very portable tool capable of measuring gaps from .020 to .100 inches. This gap gauge is sort of like a double-headed coin, in our opinion.

Not only is it about the size of a silver dollar, but once you flip it over, you also have metric measurements available. These will provide you metric measurements varying between .50mm to 2.53mm in thickness.

How does it work?

As you hold this tool in your hand, you will notice that it has a tapered edge along the outside edge. You start with the thinnest part of this tool and stick it in between your spark plug gap. From there, turn it around till you have filled the void and read the measurement provided.

There is also a small hole on the inside of this ramp style gap gauge, which can be used to increase or narrow the gap between your spark plugs electrodes.

Take care…

After using this gauge for the first time, we noticed a tiny chip off the tool’s outer edge. While this didn’t inhibit its performance, you still have to be careful if you want this tool to last a long time.

Lisle 67870 Spark Plug Gauge Gap
Our rating:4.4 out of 5 stars (4.4 / 5)


  • Only about the size of a large coin.
  • Extremely well priced.


  • The tapered edge might chip if not careful.

4 Performance Tool W163C Wide Gap Wire Spark Plug and Gauge Tool – Best Wire Loop Spark Plug Gap Tool

The next spark plug gap tool option comes from PT Performance. We are talking about their W163C model wire-loop style measurement gauge.

This tool has a unique shape to it. It features a circular body with u-shaped prongs coming out from the sides. You have multiple measurements on hand starting from .025 inches and staggered upwards to .080 inches. On the other side are the reflecting metric sizes varying from .635 to 2.03mm.

Gap spreader…

Located on this gap gauge, you will inevitably notice a jigsaw shaped piece attached to it. This black quirky shaped piece can be used for bending the overhanging wire on your spark plug.

The metal it is made from is very durable, and given that it has multiple sized notches, you will have more accuracy on hand. You do need to be careful when using this on new iridium spark plugs as it may scratch them.

Impressive performance…

We measured the accuracy of this spreader and found it to be accurate throughout all measurement sizes. Given the extremely reasonable price point, we were very impressed.

Performance Tool W163C Wide Gap Wire Spark Plug
Our rating:4.5 out of 5 stars (4.5 / 5)


  • Multiple notches for adjustment.
  • Highly accurate.


  • The material may damage iridium spark plugs.

5 Stanley Proto J000K Spark Plug Gap Ga Set – Most Lightweight Spark Plug Gap Tool

The final spark gap tool we are going to take a look at is from Proto. Their Stanley Proto J000K gauge set features eight different hooks with varying thickness to provide gap measurements.

Each bent wire hook has a decimal size and a corresponding metric size labeled. The thinnest gauge wire is 0.020 inches and goes up to 0.40 inches.


If portability is a concern, you need not worry about this gap gauge tool as it weighs a mere 0.07lbs. It might remind you of a multipurpose tool in the way that it folds together in one beautiful compact package.

The J000K also has a tool for bending a spark plug’s ground wire. This tool works well, but it doesn’t grip as well as we would like.

A rich heritage…

Other than that, the quality of this Proto tool is top-notch. Proto has been making hand tools since 1907, and their wealth of experience shows in this little spark plug gap tool.

Stanley Proto J000K Spark Plug Gap ga Set
Our rating:4.3 out of 5 stars (4.3 / 5)


  • Sturdy and accurate measurement wires.
  • Folds up into its own case.


  • A bit expensive.

Best Spark Plug Gap Tool Buying Guide

There are three main different types of tools for measuring spark plug gaps. You have ramp style gauges, feeler gauges, and wire-loop type gauges.

Ramp Gauges

Ramp gauges look like large coins and have a tapered edge around their circumference. This tapered edge will increase in thickness and has measurements etched into it.

Also located on ramp-style gauges, you will typically find a hole used to bend and adjust the ground electrode on your spark plug. Ramp gauges are easy to use, but you need to be careful not to bend them, or you will lose accuracy.

Wire-Loop Gauges

Wire-loop gauges are often similar in size to ramp gauges. The most noticeable feature on these types of measurement devices is the wires sticking out from the sides of them. The wires might be u-shaped or even shaped like a hook. Each wire will have a different specified thickness to them for measuring gap sizes.

These work well and usually include a tool for bending purposes. The only downside is that if you have an odd gap size, then they might not be able to measure it.

Feeler Gauges

The last type of gauges and our favorite is feeler gauges. These gauges might remind you of a multipurpose tool or a pocket knife.

They have multiple blades that will slide out from their casing, and each blade will have a different thickness to it. You will usually notice that one side of the blade will have metric readings while the other will have imperial measurements. Feeler gauges typically come with a lot of measuring blades.

In fact, we have seen feeler gauges with as many as 32 blades. With so many different measurement sizes available, you will have that much more accuracy available to you.

What to consider when choosing a Style?

No matter the type of gap tool you choose, you want to make sure it is calibrated accurately. Most gauges have been thoroughly tested, but with use, you still may lose accuracy over time.

You also need to take into consideration how the measurement markings have been applied to the gap tool. We tend to look for measurements that have been laser-etched into the metal, as these tend to be the most resilient when put under pressure or even bent.

Got All the Other Tools You Need?

If you don’t already have them, don’t miss our Best Spark Plugs for Cars reviews.

But, when it comes to optimizing your vehicle’s overall performance, there are several other products worth looking into. You’re going to want the Best Mechanical Tool Set, the Best Parts Washer Solvent, the Best Octane Booster, the Best Compression Kits, and the Best Flash Programmers for Tuning you can buy in 2023.

In terms of optimized road handling, our reviews for the Best All Season Tires, or the Best All Terrain Tires can point you in the right direction.

Back to spark plug gap tools…

So, what is the Best Spark Plug Gap Tool?

Well. we found the…

Stainless Steel Feeler Gauge Dual Marked Metric and Imperial Gap Measuring Tool (0.04-0.88 mm, 32 Blades)

… took the win in this roundup. The included metal housing and 32 different blade sizes make it extremely accurate and durable.

The blades are flexible enough so you can easily switch from one to another. And, you will have both metric and imperial laser-etched into the blades, making them easy to read and legible for longer.

You don’t want your car to misfire. But, with this gap measuring tool, you can rest assured all of your spark plug gaps will be as accurate as possible.

Safe and happy maintenance!

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