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.
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.
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.
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.
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.
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:
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 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:
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.
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.]
What I have learned (the hard way) about spark plugs: a) Stick with the OEM plugs unless you have a really really good reason to deviate. b) Don’t trust the “mechanic’s feel” you think you developed at age 17. Swallow your pride and use a torque wrench on spark plugs, if this is an infrequent thing for you. c) Make absolutely sure your new wires/boots make a good connection to your new plugs/coils.
Not following b) and c) has led me down some long unnecessary paths of hanging new parts. (But hey, now I have new parts.)
Yes, all true. Those ‘triple fire’ spark plugs aren’t OEM for a reason.
I’ll add a 4th suggestion: A little anti-seize on the threads pays it forward for next time. I also like to wash the spark plug pocket out before removing the old ones, to prevent the dirt from dropping into the engine.
I also line up the old plugs in the same pattern as the engine, and examine them to see if there is some anomaly I should look into.
a…a… Don’t! Read the manual. It might say, “do not put anti-seize on the tread”
I agree with the anti-seize. When you want to change the plugs five years from know, you will thank yourself for your forethought. The trick is to use just a tiny bit – don’t grease ’em up. Agreed, also, at analyzing the old ones.
Funny how all of these spark plugs and tools are from Amazon. Pay-per-click income flow… could that have anything to do with it??!! There are many more choices available at the parts store. A true comparo would have more than a single vendor to choose from.
When I worked in auto parts, the common wisdom was to stick with the original equipment or the platinum version. But back then we didn’t have 100K mileage iridium plugs available.
you have to read manufacturer’s literature. Do you think, you know better? —–
AC/Delco’s position on anti-seize
AC spark plugs should be installed dry. Do NOT use any type of anti-seize lubricant on spark plug threads. Anti-seize lubricants decrease the amount of friction between the threads, resulting in over tightening.
Overtightening doesn’t happen if you use a torque wrench.
Undertightening – and later galling or seizing – are greater risks with dry threads.
Incorrect regarding lubing the threads. Please read the following thread (one amongst many).
https://www.engineeringtoolbox.com/torque-lubrication-effects-d_1693.html
You (not you specifically) really need to make sure the read the basis of the torque specs.
Yep, always blow out the hole with compressed air before removing the plugs.
I also use anti-seize. Since plugs stay in for so long now, I even like to remove the plugs on a new vehicle just to get some on the threads to make future removal easier.
I don’t trust dry aluminum threads. When I was a bicycle mechanic through university, I was taught to lubricate every aluminum thread I turned. I’ve seen many stripped aluminum threads, but never one I lubricated.
The amazon affiliate has single handedly pushed usable reviews of ANY product off the internet. The Ancient net had great writeups for a lot of things….but when the amazon affiliate link was invented, these useful morsels of information were drowned out in a running sea of “ad copy its great click the link”.
What was useful information is now pages and pages of cut and paste ad copy.
Here is something else that many people are learning the hard way, @ToolGuy and @MatthewGuy: NEVER, EVER, EVER buy spark plugs from Amazon or eBay. All of the negative reviews are due to counterfeit plugs that are made in China and do not meet OEM specs. The counterfeit plugs will physically break, sometimes in the cylinder cavity, and cause a catastrophic failure. DONT RISK IT, NEVER use Amazon or eBay plugs. Pay a little more from an authorized parts store or get them from the dealer. Then check online to make sure you have the genuine product. There are plenty of pages (including OEM) that show how to tell a counterfeit product from a real one.
Agree. Amazon does not properly police the third-party “Marketplace” merchants on its site. Counterfeiting is rampant, in this and many other merchandise categories (even books!).
Bosch and NGK, for MY money, depending on the application.
In my experience Bosch Platinum 4-electrode and NGK rare-metal anode plugs lasted longer. But they also require an anti-seize compound if you ever want to remove them from the head again. NGK has the best selection of rare-metal anode plugs from copper-anode to platinum to whatever. Bosch and NGK plugs are Pricey, but they give hot spark, essential for complete combustion of what they call these days to be “gasoline.”
– A tool like #8 is extremely useful on some modern automobiles.
– I used to think spark plug pliers like the Lisle 52990 were useless. They are helpful on some vehicles.
– While you’re ordering stuff, get yourself a simple spark tester.
[Small engine bonus: Change the plug in your mower. And see the wire right there? It is connected to the coil. Replace the ignition coil in your small engine and you’ll think you have a new machine.]
For sure on that small engine coil. I had a 30 yr old tiller with a B&S engine that ran but sporadically. After heroic efforts working on the carburetor, a new coil (that also replaced the old ignition points setup) made it run like new! 26 bucks.
Both Snap-On and MAC sell versions of this tool. They’re surprisingly accurate from those vendors.
Please don’t replace the coil on your power equipment unless you know the correct coil gap. We sell a lot of new coils and flywheels to people who don’t. Flywheels ain’t cheap.
The danger is adjusting the gap using the hole, hooked over the end of the ground electrode – the gauge can slip, causing you to bend or break the center electrode, which can be pretty fragile on an iridium plug (I did just that recently on my of my kids’ cars, costing me $15 for another NGK Laser Iridium, OEM fitment on Kia Fortes). Better to use the kind that hooks on the side of the ground electrode.
Both Snap-On and MAC sell versions of this tool. They’re surprisingly accurate from those vendors.
Please don’t replace the coil on your power equipment unless you know the correct coil gap. We sell a lot of new coils and flywheels to people who don’t. Flywheels ain’t cheap.
I can’t believe that they are asking $5 for that cheapo spark plug gauge, I’m old enough to remember when they were $0.49 in the candy container at the check out counter. Now they are 3 times that, but not 10x that price. Of course that is what you pay for “free” shipping.
The only plugs up there I would recommend are the NGKs and then only if your vehicle came with a similar type of plug from the factory.
I remember when the Bosch Platinum first hit the market, they were very good for business. Someone would tune up their old vehicle with them and a couple of months down the road they would call me because their car ran like crap, or not at all, and it can’t be something simple like a tune up since they just did that. Fact is the ignition systems on cars designed for old fashioned plugs didn’t have the power needed to consistently fire the fine wire platinum. In some cases it would cause rotor burn through, at least on those vehicles susceptible to that.
Moral of the story use the style of plug the factory put in the car so plain old copper in older vehicles, standard platinum where called out and the fine wire style only if that is OE.
Fast forward a few years and the E3 hits the market and the whole thing played out over again, though in this case it wasn’t just older cars lacking a modern high power ignition system. They were just done in a few thousand miles.
ND plugs of yore were not recommended. Most Japanese cars listed both the NGK and ND numbers on the sticker but the majority of cars came with NGKs. With the NGKs the customer would just keep driving and at 50-60k finally get a tune up when the gas mileage dropped off. Those that didn’t win the lottery and had ND plugs would come in for a tune up at the proper 15k because the car was running crappy. At the time ND plugs were not something you could by at your FLAPS. Based on my experience with OE plugs I continued to use NGK once ND became available.
Champions of yesteryear were also know as being a short lived plug. Again no experience with the current plugs and they are now owned by Federal Mogul so they are likely better.
I used to be big on Autolites as they were like the NGK in that they tended to last the longest. However that changed when production moved to China many years ago. Shortly after the switch I had done a tune up in the wife’s car and interestingly my co-worker at the time had put a set of Autolites in his wife’s car around the same time. About 6 months later both of us got an ear full when their cars developed a dead miss. In both cases it was a bad spark plug. So 1 out of 6 were bad for both of us.
When they first came out, I ran Bosch Platinums in my ’76 Vega GT, replacing the Stone Age-technology AC R43TSX, and they worked great. I ran them at 50,000 mile change intervals. IIRC, the factory interval for the AC plugs was 22,500 miles (the ignition type was the stock GM HEI).
Jeez, Scoutdude. If your wives gave you “an earful” for that reason, I think the best method to eliminate the unwanted problem is to change out the wives.
Given that plugs last 100k these days and ECUs adjust spark timing automatically when was the last time you had to do a plug change? Maybe I’m just super lucky (knock on wood!) but I’ve never had a spark plug related problem in 35 years of driving. This includes 3 cars that have gone over 100k and 2 vehicles that have seen multiple track days. Now I’ve had several sensors fail causing misfires, two or three bad coils, two gasket leaks and an accessory belt snap so things do go bad, but I’ve found plugs are pretty robust.
“when was the last time you had to do a plug change?”
Every time my car hits the mileage written in owners manual for spark plug change
On my 3 current vehicles the spark plug changes per the “severe” maintenance schedule are due at 60k, 97k and 105k respectively. Only the 60k one was required given my current use and trade-in patterns. My point is plug changes aren’t something your average owner will encounter during their ownership period. Now my boat’s outboard engine? That’s a whole different story, every 100 hours new plugs go into that 2-stroke.
2010 Mazda3 – 75K. 1999 Villager/Quest – 105K. When I tried changing them, few had to be soaked before they came out.
@slavuta: Agreed. Despite the claim for 100k mile spark plug change intervals, I’ve had a couple cars need them around 70k miles.
I wanted to see how long I could go before I noticed a mileage drop off or miss in my 2003 Ram 1500. The plugs were supposed to be changed at 30K, but I took them to 60K without any problems and finally changed them out just before we were about to leave on a 2000 mile trip, and knowing my luck, I would blow a coil or something, so I had them changed out. They looked pretty good, not nearly as eroded as I expected. There was zero milage increase with the new plugs, but it did seem to idle smoother.
Where to start? Lets start with the plugs.
I use the plugs that are written into owners manual. If it says NGK/model#, this is what I use. However, last time I had an issue. The plugs that were in the owners manual could not be found anywhere besides eBay shipment from Japan. In this case I did use Bosch mentioned above and they work fine. When it comes to plugs, in a good engine they can last. There is no problem in the part inside the engine (for advanced plugs). Problem is the ceramic part. It becomes brittle with time. If it cracks you might have misfires and stuff like that.
Gap. If you get plugs of the model from the owners manual, no gap setting needed. They are pre-set for your car.
The tool. Interesting. Well, I have old as life tool with rubber insert. It works. If the rubber starts to come out, do this – take it out and clean with alcohol. Do same for the inside the tool. Then spray rubber with hair holding spray or even put some same-purposed balm. And stick it back in.In a little bit, it will be good to stay there and yet, if needed, it can come out.
I have a 97 Pontiac Grand Prix, bought it new, 180,458 miles, it’s still running on the original plugs and wires, starts up and runs no problems when I feel like driving it, I’m putting covid miles on my 20 Equinox with only 5300 after 10 months on a 10 k/year lease allowance!
A family member has a 2008 Saturn Outlook with the 3.6 V6. When it had about 180,000 miles on it (original plugs) it developed a bad shudder. I thought it was transmission related and took it to the shop. A set of new plugs fixed it.
Yeah, a coworker subscribes to the no-maintenance philosophy. The plugs on his 02 Maxima want 220k miles before it wouldn’t run right anymore.
I always stick with OEM plugs. My Mustang gets Motorcraft and my GM vehicles get the exact AC Delco part numbers. Plugs like those E3’s are just gimmicks. They are made in China as well. Unfortunately some legacy brands like Autolite are made in China too.
I have a gap tool like the Gapper that I got back in the 70’s and have used it for years. It is labeled Champion Spark Plugs and seems more precision made than the current one. I remember getting it free at the auto parts store where I did a lot of business. .
Wow, trolling for commissions or what? A series of product reviews which are nothing more than a restating of customer reviews on other websites should be beneath TTAC.
I’m with you jthorner. I’ve been saying this about most of their bogus “reviews” that just restate the ad copy as a basis of ranking. Of course, ranking plugs is just as absurd as the one they did on “best” engine coolants. Fortunately it seems from the comments that readers know to put in what the factory did and disregard these ridiculous comparisons. I’ve always used factory plugs for My own and customer’s vehicles, and even fixed a few drivability issues from the wrong plugs. For example, I wouldn’t put a crappy champion plug in a lawnmower, but not using them in Chrysler products that call for them can lead to issues. It’s sad that TTAC has fallen on such hard times. I would have thought the car and product ads in the same font and format as regular articles would be enough, but I guess not. That being said, their recent review of garage organization products was actually good, because the author actually tried them and had unbiased experience.
Did you pay a fee to enter this site? No? Me neither.
This is precisely because features like this help pay the bills.
Unless you want this place to create a paywall, I would view such “features” as personal friends who save us money.
Possibly interesting factoid: Champion spark plugs and AC spark plugs are both named for the same guy.
https://en.wikipedia.org/wiki/Albert_Champion_(cyclist)
[Not the ideal way to die.]
One thing that surprises me about the list above is that, under ‘cons’, there’s no mention of the fact that there is simply no good way to adjust the gap on E3 spark plugs due to their design. Granted, this could be said to apply to any multiple-electrode spark plug to one degree or another, but when you’ve got more than two electrodes the ability to change the gap becomes considerably more difficult.
Moving on to personal opinion of that product: E3 plugs are snake oil. I’ve bought three cars which had them installed, and all three ran like crap until the plugs were replaced with something more conventional. They weren’t misfiring or anything like that, but performance and responsiveness were definitely blunted by them. Checking the model numbers of the E3 plugs that were removed showed that they were the correct ones for that engine in every case, so these do not appear to have been cases where incorrect plugs had been installed.
Single-electrode Bosch platinum spark plugs have been my go-tos for probably around 20 years at this point. They last well, provide good running, and aren’t horrendously expensive.
I replace spark plugs when the manual recommends, which is my SOP for all maintenance. I tend to use the irridium versions that are on sale.
When my 2015 Mazda6 hit 100k miles, it was operating perfectly. Upon spark plug replacement, it seemed the engine operated exactly the same way, but I did notice about 1.5 mile per gallon improvement in my fuel consumption.
(I manually calculate fuel efficiciency at nearly every fill up. My 95k mile car was averaging about 32 mpg before the plug change, and now a bit better than 33 mpg at 118k miles–the same as when new–my daily commute and driving style is unchanged)
As many of you understand, engine control units constantly adjust timing, fueling, etc., and such systems do a great job of hiding minor fluctuations in spark plug efficiency. As such, it is nearly impossible to “know” when your good running engine “needs” new plugs, but when you do replace them on schedule, I reckon you are doing yourself a favor in terms of fuel efficiency..
My 2003 Ram 1500 was supposed to have it’s plugs changed at 30K, Champion Copper Plus, I think they were. I decided to wait until it started to run bad or the mileage dropped before I changed them out. When the truck hit 64K, I made the decision to keep it and save my payment money for a new vehicle, and I had the dealer change the plugs and clean the throttle body and intake. I was planning to buy new tires and do anything else it needed. Brakes had been done already a few months before. I expected the original plugs to look very worn, but they looked pretty good! The center electrode was rounded off pretty much, but that was it. After I got it back, it still got the same terrible mileage, (About 12, it did go up about .1 MPG), and it didn’t seem to run any differently at all.
I got hurt in Nov of 2007, and the Ram had to go, too high for me to enter safely, and I traded it in on an ’08 Charger R/T. One of the service techs at the dealership bought it, and it was a great truck for him. He just sold it to his neighbor to use for boat towing. It has about 220K miles on it now, and other than normal wear items, it had to have a sensor replaced, and a couple of coils too, it’s been about as good as a truck can get. I consider that truck #2 on my list of great vehicles, with my present Scat Pack Challenger being #1, with my heavily modded ’79 Trans Am being third. My ’82 K5 Blazer is the clear winner at being problem free, having gone about 48K miles with a headlight and a battery as the only problems it ever had, period.
Do NGK Iridium spark plugs increase horsepower?
Years ago, Champion was one of my favorite spark plugs then I started using Denso and NGK. My 2000 Ford ranger runs well with Denso TTs vs the stock Motorcraft single tip plug and the over rated Autolites. The NGK laser platinum for my 2007 kia optima and IR for my 2014 Mazda. Personally I use hand feel for all my tune ups, but I also noticed years ago Champions had a tendency to crack. I tried the Bosch in my kia and the car started to skip. I returned them to Advance Auto Parts and never tried them again. Denso and NGK are my go to spark plugs.
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.
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