Sparking Your Interest: Best Spark Plugs

Nov 07, 2023

It has been ages since the days when one needed to change the spark plugs in their car every 20,000 miles. Today’s machines are very different, to the point where most owners have no idea the firing order of the engine that’s powering them down the road. Still, plugs do need to be replaced eventually, even if it is at 100k.

Like the recent oil filter post, we selected spark plugs listed to fit a car that is likely representative of a typical daily beater: A ten-year-old Civic. All the same, we probably should have selected a 1992 Oldsmobile Cutlass Supreme SL (not the International Series – too fancy) if we wanted to be representative of the Best & Brightest.

We’ve thrown in a couple of spark plug tools for good measure as well because, like the authors at this site, our readers have probably lost theirs at the local pick-n-pull.

It's difficult to recommend against OEM stuff; after all, who knows your car better than the people who built it? While DENSO is about a third-owned by Toyota and its subsidiaries, a good many Honda products come fitted with items from this parts maker as well.

This six-pack will leave you with two extra plugs, causing you to wonder in five years' time why you have a pair of spark plugs to fit a Honda Civic you no longer own. The seller is offering free shipping anywhere in the States and its reviews are largely positive.

It's difficult to recommend against OEM stuff; after all, who knows your car better than the people who built it? While DENSO is about a third-owned by Toyota and its subsidiaries, a good many Honda products come fitted with items from this parts maker as well.

This six-pack will leave you with two extra plugs, causing you to wonder in five years' time why you have a pair of spark plugs to fit a Honda Civic you no longer own. The seller is offering free shipping anywhere in the States and its reviews are largely positive.

Here’s a weird one. Normally your author wouldn’t hesitate to recommend the Bosch brand in this situation and confidently place it atop our post. However, despite garnering a solid 4.5 out of 5 stars, there is feedback calling this plug out as bearing quality less than one would expect from the Bosch brand, along with delivery issues.

A few customers railed that these plugs were made in a different market than the Bosch home country of Germany, which may or may not be true. Reports of physical breakage could simply be chalked up to hamfisted DIYers being too happy with a torque wrench. There is a recent report of a customer being sent a single plug instead of four, though that person did get their money back. Nevertheless, your author has always had good luck with Bosch-branded products, warranting their inclusion here.

Here’s a weird one. Normally your author wouldn’t hesitate to recommend the Bosch brand in this situation and confidently place it atop our post. However, despite garnering a solid 4.5 out of 5 stars, there is feedback calling this plug out as bearing quality less than one would expect from the Bosch brand, along with delivery issues.

A few customers railed that these plugs were made in a different market than the Bosch home country of Germany, which may or may not be true. Reports of physical breakage could simply be chalked up to hamfisted DIYers being too happy with a torque wrench. There is a recent report of a customer being sent a single plug instead of four, though that person did get their money back. Nevertheless, your author has always had good luck with Bosch-branded products, warranting their inclusion here.

There's a good bit of redundancy in that title but we wanted to make sure we're pointing you to the correct pack of plugs. E3 spark plugs came on the scene in the late '90s, with copious amounts of advertising during NASCAR races and on Speedvision (remember when it was called that?).

E3's unique design is promoted as forcing an edge-to-edge spark discharge, which is apparently the best way to get a spark to leave a surface. They say their DiamondFIRE electrode projects the spark further into the combustion chamber, bringing it closer to the most robust air/fuel mixture.

There's a good bit of redundancy in that title but we wanted to make sure we're pointing you to the correct pack of plugs. E3 spark plugs came on the scene in the late '90s, with copious amounts of advertising during NASCAR races and on Speedvision (remember when it was called that?).

E3's unique design is promoted as forcing an edge-to-edge spark discharge, which is apparently the best way to get a spark to leave a surface. They say their DiamondFIRE electrode projects the spark further into the combustion chamber, bringing it closer to the most robust air/fuel mixture.

The NGK brand brings a more traditional spark plug design to the party than the oddball E3 just mentioned, with a single-hooked tip providing the spark. As referenced in their name, NGK says this plug’s laser-welded iridium center electrode tip ensures high durability and better spark.

It is said to be designed with a platinum disc welded to the backside of that ground electrode to provide a long life compared to other brands. Um, ok - we'll take your word for it. The insulator on these things is said to be longer than average (place crude joke here) which apparently will help prevent fouling if you still live in the 1970s.

The NGK brand brings a more traditional spark plug design to the party than the oddball E3 just mentioned, with a single-hooked tip providing the spark. As referenced in their name, NGK says this plug’s laser-welded iridium center electrode tip ensures high durability and better spark.

It is said to be designed with a platinum disc welded to the backside of that ground electrode to provide a long life compared to other brands. Um, ok - we'll take your word for it. The insulator on these things is said to be longer than average (place crude joke here) which apparently will help prevent fouling if you still live in the 1970s.

Champion has been around seemingly forever and, as happens when things are around for a long time, public opinion can wax and wane. This also holds true for restaurants, websites, and spouses.

Sold by the each, this particular fitment of Champions has a terrifying lack of real-world reviews but that could be chalked up to a recent relisting of the item or creation of a new ad. Other plugs from the same brand seem to hold up well in the court of public opinion.

Champion has been around seemingly forever and, as happens when things are around for a long time, public opinion can wax and wane. This also holds true for restaurants, websites, and spouses.

Sold by the each, this particular fitment of Champions has a terrifying lack of real-world reviews but that could be chalked up to a recent relisting of the item or creation of a new ad. Other plugs from the same brand seem to hold up well in the court of public opinion.

That's Pulstar, not Pulsar, so get any images of neato Nissans from the '80s outta yer mind. This crew promotes their spark plug as having an "innovative plasma-assisted combustion technology" which isn't worded entirely accurately since the plug itself does not combust. At least, it shouldn't.

Claims of output increases numbering up to 7 horsepower and 9 lb-ft of torque should be taken with a heavy grain of salt since these measures are often difficult to capture and prove beyond the shadow of a doubt. They get extra points for using the term "wicked" to describe the idle and throttle response these plugs apparently provide.

That's Pulstar, not Pulsar, so get any images of neato Nissans from the '80s outta yer mind. This crew promotes their spark plug as having an "innovative plasma-assisted combustion technology" which isn't worded entirely accurately since the plug itself does not combust. At least, it shouldn't.

Claims of output increases numbering up to 7 horsepower and 9 lb-ft of torque should be taken with a heavy grain of salt since these measures are often difficult to capture and prove beyond the shadow of a doubt. They get extra points for using the term "wicked" to describe the idle and throttle response these plugs apparently provide.

Your author prefers this type of spark plug gap tool compared to the ones with whose measuring arms fan out like a peacock's tail. Why? Absent of any moving parts, there's less to break.

A few respondents railed against this thing for unreliable measurements but it should be noted that this thing only costs five bucks. If you're in the business of professionally rebuilding engines, one would hope you'd splash out the big bucks for a pro gap tool. The rest of us will make do with this one on the occasional time it's needed.

Your author prefers this type of spark plug gap tool compared to the ones with whose measuring arms fan out like a peacock's tail. Why? Absent of any moving parts, there's less to break.

A few respondents railed against this thing for unreliable measurements but it should be noted that this thing only costs five bucks. If you're in the business of professionally rebuilding engines, one would hope you'd splash out the big bucks for a pro gap tool. The rest of us will make do with this one on the occasional time it's needed.

Ok, champ. You’ve bought one of the recommended spark plugs above gapped the thing perfectly. Now, how are you going to install the things? That’s right; with a spark plug tool similar to the one listed here. If you're this deep into the task, you're going to appreciate the swiveling action of this tool.

Spark plug sockets are designed to grip the plug securely - this option uses a magnet for that job. Customers report this works just as well or better than the rubber bushing found in competing tools. Reviews are beyond stellar, accumulating a stunning 4.8 out of 5-star rating based on nearly 4500 reviews. That doesn't happen by accident. Or with a bad product.

Ok, champ. You’ve bought one of the recommended spark plugs above gapped the thing perfectly. Now, how are you going to install the things? That’s right; with a spark plug tool similar to the one listed here. If you're this deep into the task, you're going to appreciate the swiveling action of this tool.

Spark plug sockets are designed to grip the plug securely - this option uses a magnet for that job. Customers report this works just as well or better than the rubber bushing found in competing tools. Reviews are beyond stellar, accumulating a stunning 4.8 out of 5-star rating based on nearly 4500 reviews. That doesn't happen by accident. Or with a bad product.

FAQs

Which type of spark plug is best?

Well, it depends on what your definition of ‘the best’ is. In general, three types of spark plugs are available in the market, namely:

Copper Spark Plugs

These are the most common ones. Because copper is a good conductor of current and is a cheap metal, copper spark plugs don’t cost much, and deliver more power while driving. Therefore, many times, these plugs come as a company-fitted piece of equipment when you buy a new car.

On the downside, because copper is comparatively a softer metal, these spark plugs are likely to wear down more frequently, especially when installed in vehicles that produce more heat when in use. This is why copper spark plugs are considered less durable and the professionals recommend replacing them with the new ones after every 20,000 miles of the drive.

Platinum Spark Plugs

Platinum is a harder metal when compared with copper, and therefore platinum spark plugs have a higher melting point that makes them last longer. As a result, these plugs can run for around 100,000 miles, before they need to be replaced with new ones. In addition, platinum spark plugs gain more temperature when in use. Because of this, they can easily burn the unwanted deposits off their body, hence offering improved performance.

Platinum spark plugs come in two variants, namely:

Single Platinum Spark Plugs – These have one platinum disc that is welded to the central electrode. Due to this, these spark plugs are almost as efficient as copper ones

Double Platinum Spark Plugs – In these plugs, a platinum disc is welded to both central and side electrodes, thus making them more efficient

Iridium Spark Plugs

With a melting point of around 700o higher, iridium is approximately 8 times stronger and 6 times harder as compared to platinum. This makes iridium spark plugs the most durable amongst its competitors by offering around 25 percent more lifespan than platinum plugs.

On the downside, iridium spark plugs are most expensive as the metal cost is significantly high.

Considering the above details, it would be best to pick iridium spark plugs whenever possible. On the other hand, if you need a good balance between cost and performance, you can go for platinum spark plugs. When it comes to copper spark plugs, they are the cheapest, and yet offer optimum performance and durability.

Pro-Tip

If your vehicle came with spark plugs of a higher quality, when the time comes, you are strongly advised to replace them with the ones of the same or better quality. For instance, if your car came with platinum spark plugs, it would be wise if you either use the platinum plugs, or go with the iridium ones. It is NOT recommended to downgrade to copper spark plugs as you may experience some performance and efficiency issues while driving the vehicle.

Do iridium spark plugs make a difference?

Yes, they do. Because iridium spark plugs have the central electrode with a fine quality wire, and because iridium itself is a stronger and harder metal with a higher melting point, these plugs last longer, offer increased firing efficiency, and can even conduct the electrical energy in a better way.

What spark plugs are better than NGK?

It depends on the car and its anatomy. In any case, it is always advisable to stick to the OEM brand as it would give you the best overall performance.

If you still want to switch to a different manufacturer, make sure to check which car do you have. If it is from a Japanese manufacturer, Denso spark plugs would be good, and even the company has more factories than NGK. Likewise, for German cars like BMW, Volkswagen, Mercedes, etc., Bosch spark plugs would be more suitable.

Do better spark plugs make a difference?

Yes, they definitely do. If a spark plug is of good quality, you can expect improved firing efficiency and better electrical conduction. Also, because good spark plugs use high-quality metal like iridium, they offer enhanced performance and comparatively increased lifespan.

From time to time, TTAC will highlight automotive products we think may be of interest to our community. Plus, posts like this help to keep the lights on around here. Learn more about how this works.

(Editor’s note: This post is meant to both help you be an informed shopper for automotive products but also to pay for our ‘90s sedan shopping habits operating expenses. Some of you don’t find these posts fun, but they help pay for Junkyard Finds, Rare Rides, Rental Reviews, and whatever else. Thanks for reading.)

[Main Photo Credit: Evgenius1985/Shutterstock.com. Product images provided by the manufacturer.]

My '02 V10 Ford SuperDuty is still on the original plugs after 20 years and 180k miles. It runs perfectly and still swills gas like Jack Daniels so no change since new. Even the Ford dealer says leave 'em in there until it starts to run poorly, likely because he's a scared as I am of the fragile plug holes on these engines. But since no problems, no worries.