Do Spark Plugs Matter? CHEAP vs EXPENSIVE | Engine Masters | MotorTrend

[@MotorTrendWatch]

Did any of these test results surprise you?

[@idriftgodly3299]

No Pulstar Plasma?

[@crispincurtis8585]

Good video🤓🤙

[@77zrod46]

No!!! What about I indexing a plug?

[@danyan7]

no surprise, in 2022 i change plug from a 1999 bmw 328, it had a original ngk bkr6equp four electrodes maybe never changed in 180.000 miles because coils are stuck, i need to pull that hard that i move the car pulling, plugs was very worn very visible all four electrodes worn,i wanted for perferomance plug iridiun, copper, dual electrode, but i thouth that it will be the same and ended buying the same bkr6equp, i didnte feel any change whit the new ones. i imagine that more electrodes are good for old cars and help wiht misfires only

[@dhooter]

Nope they serve only one function. But I'd like to see you guys test indexing plugs. Does that make any difference?

[@theelifeofdez381]

So get regular plugs and open the gap a tiny bit.

[@jeffreyhinman1397]

I’m wondering about economy though, you get more power but does it cause loss of mileage... probably so. Could get a little more or less wish they could tell.

[@ts46176]

Thanks for ruining the whole video for me lol

[@theelifeofdez381]

@@ts46176 Lmaoo sorry g

[@theelifeofdez381]

@@jeffreyhinman1397 yeah video was too short

[@brokenwrench404]

@@ts46176then you should of watched the whole video before going into the comments to behave like a Karen

[@BuzzinVideography]

O'reilly's manager here... I NEVER have NGK or ACDelco brought back with problems. Other, cheap brands, have had issues. Last week a guy brought back a set of autolight APP65 that lasted 5,000 miles and the electrodes were GONE. Ground straps ghosted. All of them. He replaced ACdelco plugs after 90,000 miles.

[@Shanonmcnab576]

Wow autolight?? I’ve never used them myself but I always see a lot of good reviews by others who use them.

[@BoostedPastime]

I have never heard good about autolite​@@Shanonmcnab576

[@gordocarbo]

Been running autolite 3924s for decades in my hot rods never had a miss misfire failure nothing. Hes got another issue if the straps are disappearing. Delcos out of my 02 Silverado I changed at 110k just to do it...sure they needed changed but worked great.

[@SophiaAphrodite]

My guess is he did not gap them right or damaged them when gapping

[@gordocarbo]

@@SophiaAphrodite Agree...or car had detonation issues. Been using autolites since the late 80s never had an issue

[@PhattyMo]

I've always had the best luck with regular NGK plugs. Smoother running,fewer misfires..overall better. They just work like a spark plug should..I've tried quite a few other plugs,and always go back.

[@zenden6564]

I'll second the motion 🙂

[@StupidBlokeStupidVideos]

Same here. And Bosch are the ones I’ve had most issues with.

[@sigmamale4147]

Ngk or denso... best brands for igntion stuff

[@SpecialAgentJamesAki]

Agreed. They also have really really good rust prevention and sooooo many more options than other brands great for really niche builds and stuff where you need something super specific.

[@marinusk67]

I throw standard NGK plugs out of my motorcycle's immediatly. Better milige and starting and smoother running with Nippon denso. Older bikes is it more noticeable

[@raiderjohnthemadbomber8666]

I run a 1974 Nova with original Gen I 350. I installed O2 sensors on a dual exhaust header combination. This allows me to monitor performance and fuel economy and know whether the problem is isolated (plugs, etc.) or general like carb, distributor, etc. Using a carb I also run a vacuum gauge. This system has served me well. I do open plug gaps routinely and get enhanced performance in every situation.

[@bradfordeaton6558]

Chris Jacobs in his book on ignition systems points out that the main concern is the flame kernel. A wider gap requires more wattage to jump and produces a bigger and hotter flame kernel. The multi electrode plugs just mask the kernel from various directions. He goes into much greater depth than this but for the purpose of this post, it's pertinent. The simple Autolite plug with the wider gap produced the most power. And cheap(ish)!

[@HITTHEHAZARD]

Testing and comparing different parts on this channel are my favorite episodes 🙌

[@misterpacha1]

The channel sucks so bad that this is your favorite. Have u not seen the masterpieces from this channel from. The past. The reviews and shows from 4 to 5 Yeats ago? Now hagerty is the new motortrend.

[@Tigrisshark]

For me it's the three presenters. I'll never get anywhere near building an engine, but listening to theses three is just awesome.

[@MotorTrendWatch]

Who said science can't be fun?

[@jbcowherder6210]

so i can attest to the longevity of Irridium/platinum plugs in an engine WITH a ignition system designed to use them: as a retired ex-Toyota technician for the last 25+ years i can say multiple times we had customers bring in vehicles with over 200k on the original irridium/platinum plugs that were installed at the factory- still running strong. what really matters is proper design, and using the proper plug for the engines ignition system is key.

[@xinjinping8113]

Honda Technician here with over 65 years experience, Copper everyday. Reason? Always fresh installs during intervals. Nothing beats a fresh plug, especially made with the best conducting material.. Copper. Copper also on BMW.

[@davidvaughn7778]

My take is this: 1. If youre racing/ like to tinker with things go copper. They are cheap if they foul etc. When/if they foul up or otherwise wear out you have an excuse to tinker again. 2. If youre putting plugs in your daily driver grocery getter, go ahead and spring for the platinum or iridium plugs. They really do last a long time. If i remember correctly, platinums have a 100k mile life expectancy.

[@baddriversoflittlerock8359]

I know GM rated there platinum up to 100k, but I realistically got 60-75. Never got 100k w/o a missfire.

[@SaveThePurpleRhino]

But the ordinary plug cost significantly cheaper, won't that offset the platinum/iridium longevity ?

[@robertdietz1732]

@@SaveThePurpleRhinoold thread but people forget to place a value on their time. Replacing plugs multiple times adds cost just in time and effort.

[@dastardlyman]

in one of david vizard RECENT books he says a small amount of plug resistance is best ie 200ohms they often come with thousands of ohms. lets be even more clear he measured the resistance in the plugs and leads combined. ignition is VERY important if you have a chamber that is hard to light up.

[@adamarndt7617]

Yep. In addition to reducing EMI, the added resistance increases the DURATION of the spark event which helps ensure that you don't have a misfire. You need some fuel molecules to be present in the gap while the spark is firing. You need to trade off max voltage vs. getting a long-enough spark event duration.

[@jkim6200]

From the seat of the pants perspective riding on a motorcycle, opening the gap up seems to be effective on high compression early 1990's GSXR, but it actually seems to work against, by sapping a little power, on a lower compression Honda Cub clone.

[@DoRC]

Man the E3 plugs were the only ones I really wanted to see. Re-test!

[@jameseroh6544]

I found that using Autolite Platinum and Double Platinum spark plugs gave the best power and fuel economy at part throttle operation. When I used the Autolite plugs in 7k watt Honda generators that were running air conditioners at a remote site 24/7. The tank of fuel would last 8.5hrs, up from 6hrs with the standard plug. Running Mobil 1 oil instead of conventional multigrade oil, added another hour to the run time. On the dyno, what were the differences with the BSFC?

[@joshghazi]

im so glad engine masters is back on youtube, its been years since ive watched one, also, missing the coolest sparkplug which is a pulseplug with built in capacitor, also plugs wont really shine unless you and increase the pressure inside the cylinder until it cant jump the gap. also other factors to consider is the sparkplugs ability to light up ultrarich or ultra lean mixes, some plugs will perform better than others depending on its design and how it creates hot spots in the cylinder

[@CarsandCats]

Forgot to add that you CAN make more power with side gapped Autolite Racing plugs, but they don't last long on the street as the gap opens as they wear because it eats the edge of the electrode off.

[@rainsf0rd]

great episode boys! While a larger gap will net you a bit of power on a NA setup, the same cannot be said once you go boosted. Why? Spark kernel strength! Keeping a larger gap can, effectively 'blow the spark out' as you add boost. For example, you might have shrink your plugs from 32 thou down to 28 or 24 thou once you've increased boost. I think the rough rule was 4 thou for every 50 HP, and swapping to a colder range plug also helped. Would love to see you guys explore spark plug gap on a boosted setup as well! Cheers, - rains

[@MrLuvtheUSA]

I had also asked them to explain "colder" plugs and the reasoning behind using them. I don't exactly know what it means for a plug to be colder, or why it might be desireable

[@rainsf0rd]

@@PeterAngles absolutely it is. BUT, There should be a rudimentary consideration for boosted VS NA applications when considering spark plug gap, temperature range ... If we wanna be ostensibly objective ;)

[@scotteddy9960]

Old vid but I've run NGK for everything since I was young. They've never failed. Playing with spark gap is nothing new. Cool to see it tested again. E3 has unmatched mpg gaines. Keep up the awesome work💪

[@tkaald]

I rarely change spark plugs but give them a clean annually. Replace only if one has failed. My 1963 Mountfield lawnmower still start on the first pull and runs well on the original Champion spark plug from 1963 which is 61 years ago.

[@volvobrynk]

The Bosch commercial Said it was for longevity they went with two straps and because when they fouled At idle, it had a chance of cleaning it out at more the half throttle. The same with Imodium, they started with being 3times as expensive, and lasting 2-3 times as long, results may very. But over time we went from a 500km of a plug life on carb engines, til 15k km-beyond on EFI. Just curious, if you get less power, at more gap, then less gap, your coil is too weak. I know, it tops at a point, but more gap, more spark.

[@johnhufnagel]

What I'd like to see tested is: Strain on the ignition system due to wider plug gap. More gap means higher voltage needed to strike the arc. Also what affect does gap have in boosted applications. Does gapping more or less effect power, potentially because of spark blow out.

[@bradgriffith4231]

Narrow gap is required on boosted engines because the forced air will literally blow the spark out.

[@MarcStollmeyer]

I have a high compression motor, 30 thousands it wont start 18 thousands it goes to the moon. Smaller gap required more pressure you have.

[@joefries7046]

ive always seent he e3 plugs make vehicles missfire. on 3 totally different engines. Never seen an NGK iridium go bad or perform bad. Always work good for me

[@spiffcats]

When I got my old 76 chevy with a 350 in it I had it for almost 10 years without ever touching the plugs. Eventually after sitting under 5 or 6 feet of snow like it used to do one winter I fired it up and it had an occasional misfire, nothing bad but enough I guessed a tune up was do. I don't know what brand these plugs were, but I hadnt touched them in 10 years and it didnt look like the previous owner had done them recently either, they were rusted solid into the holes, I barely got them out. I cant believe they were still working at all, impressive. The best spark plug I have ever used was in my 4.3 vortec. It has 4 points instead of the normal 1 and it did increase fuel economy by about 2mpg.

[@abc-bm8pl]

More power with a wider plug gap should have been expected. More fuel/air mix is ignited at the spark event, so the flame propagation gets a head start in comparison to a smaller gap. It's equivalent to a tiny bit more ignition timing.

[@ChristopherHallett]

The spark has a greater distance to clear so it doesn't make the jump until the voltage spark from the coil has climbed higher, thus the spark is hotter, too.

[@jaymorrison2419]

@@ChristopherHallett Id really be interested to see this again testing plug temp. Or something in a boosted application.

[@deanmeyer1815]

As long as the ignition system can handle the additional current to jump the wider gap at high cylinder pressures, there is a better chance of having the air/fuel mixture passing through the gap to ignite.

[@bongtoadboobender3921]

With a wider gap under boost wouldn't a closer gap be better to avoid the spark from being blown out from the pressure I closed mine from .60 to .30 when adding a turbo at 8 psi

[@TheLionAndTheLamb777]

@@bongtoadboobender3921 Turbo or Supercharged you would want to run a smaller gap for that reason, but still the same applies that a larger gap if you're able to run one is better for a bit more power.

[@zokusharuuku1091]

I think what might be important to talk about is spark plug gap under boost. When I turbocharged my mr2 spyder certain spark plugs would misfire as soon as boost hit at 2 psi yet ran perfectly fine naturally aspirated. I learned it was because the fuel would blow out the spark meaning i had to have a smaller spark plug gap.

[@forterierocks]

Have you ever done an episode on air filters? Like is it worth the money for a K&N over an OEM replacement or whatever the parts store has🤔

[@nealcoppola9963]

A proven benefit from a slightly wider plug gap -- it can help lower HC in a Tail Pipe Emission Test on a Carburated Engine.

[@diyman25]

Come from NA Rotary race world I am believer of wider gap will make slightly higher hp But recently learn u need to reduce the gap when u are at E85 flex fuel tune with boost 😅

[@MikkellTheImmortal]

It doesn't happen often, but I learned literally nothing from this episode. I'm actually quite surprised at that. So in the interest of education, I will provide a little. The reasoning behind the multiple grounding straps is to give the arc a greater chance of developing, reducing the possibility of misfire. Tip for your old copper plugs when you open the gap, you can leave your gap coin in between the strap and plug and using pliers you can push the strap back over to the center while maintaining the gap (only works with gap coins).

[@mariocooldude9092]

And aren't you also unshrouding the spark kernel to better ignite the air/fuel charge with this design? I read in old car magazines an old racer trick is to cut the ground back so it's no longer over the center electrode...with this design you're basically getting that out of the box ...I'm surprised they didn't mention that

[@bradleycrenshaw6778]

well i learned that I wasted a lot of money on gimmick spark plugs.

[@joshreynolds729]

That’s great and all but kids are going to thing oh just open that gap up on my newer style x car to gain a few ponies not knowing how tight of clearance they have before tdc takes the top off. They are using an older big block Chevy. This is why manufacturers have specs for this.

[@kleinbottled79]

Leaving the gap coin in is so obvious... once someone says it. Would have saved me 5 minutes a few weeks ago. Thx

[@ironmaiden5658]

And having the straps on the side and not the top means the plug is shorter as well. But you're right. This was a pretty useless video.

[@Tokey_The_Bear]

I dont care what anyone says about complaining about a paywall, you guys still give the best real gearhead content anywhere.

[@royboy620]

Not anywhere ,we can't watch it in Australia anymore .😢

[@danb2122]

I’ll buy the iridium plugs for my daily driver so they last longer. My classic, I’ve always ran autolites and never had any issues or problems. Ive always thought those multi ground strap plugs are a waste of money.

[@67daltonknox]

I put Autolite iridium plugs in my Tundra because they were on sale, 1/3 the price of the NGKs. 30K miles later they are running fine.

[@superspeeder]

I’ve seen repeatable low-rpm driveability improvements going from an OEM iridium plug to a basic NGK “copper” plug one or two heat ranges colder. No long-term fouling observed, just far more frequent gapping required (like every oil change). This was on a small turbo four cylinder with a manual transmission.

[@superspeeder]

@@Thycatboss if you Google “Cruze Hesitation Gone” there’s a 65 page thread discussing the improvements seen. Lots of testimony from many owners.

[@DustinGould]

My yamaha grizzly 660 never started in the cold --- numerous different plugs and tuneups --- E3 spark plug made it start in the cold--- for my yamaha it seriously made a difference

[@4BillC]

I prefer NGK copper plugs in my 1.8 turbo gapped to .028 I put 20K+ miles on them! And at just over $2 each... It's a win all the way around! I wish I would pay almost $20 for a single platinum plug!

[@randr10]

I actually noticed this gap thing with plugs on an old Saturn that I had. I was trying to eek out a bit more power from that little 4-banger, but things that make power often translate to MPG and I consistently got better mileage with that car when I ran bigger plug gap. My setup was Accel coil packs and NGK plugs with I think 0.055" gap (it's been over a decade so forgive my poor memory but I do know it was significantly more than the OEM spec of 0.040"). I tried this with the factory coils and it would not run right with those so I know the higher voltage coils made a difference. On a highway trip shortly after I did the mods this car got 42 mpg, which is pretty good considering that those cars are EPA rated for 32. I don't know if power changed at all but it did feel faster. I read from some people who know more than me about those cars that the tune was a bit rich from the factory, so maybe the extra gap was helping get more complete combustion on that rich AFR. I don't know exactly why but the results were way better than I expected, especially the mpg. I did some other mods to that car, which was quicker than you'd think due to its lightness, but that plug gap/coil upgrade thing was a big surprise for me. It yielded the best results.

[@skippy2987]

Missed opportunity here. The dual electrode plugs can be used as factory side gapped and extended electrode plugs. If you index them it should be the equivalent of a degree or so of timing, but less knock risk than normal timing advance

[@rad87gn]

Spark plug heat ranges is important to help keep plugs clean and not melting. Reasons to go lower temp when you add power adders like turbo, blowers, and NOS.

[@Parents_of_Twins]

How is the heat range developed? Resistor in the plug? V=IR so increased resistance equals a colder plug?

[@TheLionAndTheLamb777]

@@Parents_of_Twins No, resistor plugs have nothing to do with heat range. It's the inside ceramic design difference that determines the heat range.

[@Demoralized88]

@@Parents_of_Twins Spark Plug Heat Range actually refers to the thermal conductivity of the entire spark plug itself and nothing electrical. Hotter plugs dissipate less heat into the cylinder head, making the exposed plug inside the chambers run hotter for the purpose of limiting deposits on the plug that may interfere with good spark between the strap and electrode. Conversely, colder plugs are desireable for performance reasons to move as much heat out of the chamber as possible but if too cold a plug they will be prone to deposit fouling, especially if running rich and/or burning oil. Stock plugs are always much hotter than necessary to accomidate a wide range of conditions/uses to ensure fouling won't occur and because engines have been running increasingly hot to minimize certain emissions.

[@SvdSinner]

In the olden pre-ECU days, spark gap made a difference in timing. Now, the ECU compensates to keep timing the same. A larger gap simply means a bigger, longer spark to increase ignition efficiency. An interesting test would be running a consistent gap vs plugs with varying gaps.

[@bradgriffith4231]

Modern fast burn heads have reduced the ignition timing lead required to fully ignite the mixture. My 409" SBC with World heads runs exactly the same with 32* timing as it does with 36* & 87 octane as 105. E.M. has a test on fuel from 87 to 115 octane & the timing & mixture required was the same for all.

[@johnpickelheimer4782]

I run autolites in everything I own.. never had a problem

[@Guardducks]

Had a friend who tried three old split fire plugs his truck ran terrible and switched back to his old plus his truck loved them.

[@toycoma98]

Can u test ruthenium spark plugs.

[@MyCrazyGarage]

I think the difference is mostly longevity. From personal experience i can tell that a normal copper plug makes the same power as an Denso Iridium plug (best type i know) IF you have a good ignition system. I used to always put Denso TT (twin tip iridium) in my engines but found it rather expensive since a lot of race engines run rich at startup and idle, which results in very short plug lifespans. I often had new plugs that died because i ran an engine for 20 seconds before shutting it off. (no, theyre not fouled or dirty, internally broken from stress). Normal Copper plugs work just as good and wont die as fast. Get a good COP or IGN-1A coil and youre good to go. Of course dont forget heat range and gap :)

[@TheLionAndTheLamb777]

If you have a weak ignition coil sometimes a fine wire electrode plug will idle a bit smoother. Other than that it's just the longevity.

[@dunercr]

I’m actually curious about the NGK surface gap plugs for tight tolerances 🤔

[@methanial73]

What about capactive discharge plugs? They basically spark on a flat surface. No ground strap.

[@davidphillips3953]

I experimented to the extreme with the plug gap one time and completely removed the strap in all 16 plugs in a 2011 ram I swapped a 6.4 hemi into and it idled very noticeably smoother with lower throttle opening and part throttle was smoother and run a slightly lower throttle opening to cruise at the same speed but it went into misfire bigtime over about 50 - 75% throttle opening. I think bigger plug gap helps as long as your ignition can jump the gap under the most extreme conditions your engine can throw at it.

[@n.mcneil4066]

During the early 50's Autolite advertised that their resistor plugs gave a better idle. Chrysler used Autolite & they increased the plug gap from .025" to .035" in their cars.

[@TonyYork-KB9RAO]

I used the Bosch plugs that had 4 grounds , I dont recall the name, in a 92 chevy truck (5.7) that had 160K, when the plugs were installed, i gave the thing to my dad at 290K and using a quart of oil every 800 mies never fouled a plug...

[@SANDSCORCHER]

That Chevy sounds just perfect 👍🏻 Interesting to see how much power those basic plugs made.

[@natricjol]

the larger gap allows more of the a/f mixture to get close to the spark. that is why I run the twin-tip plugs. be interesting to see how they run on here between stock, 20thou, and 65thou.

[@BIGTONY2132001]

Back in my days of drag racing I have tried every spark plug and gap from .020 to .065 gap from Autolite to VGroove and the ONLY plug that really did prove to pick up power was the old Champion Black Copper truck plug. Tested and proven in a SBC 377 inch with AFR heads picked up a 10th in E.T. and 1 mile per hour. ran 9:50 141.75 mph.

[@jagmarc]

i just wrote a similar experience with me it was a champion L87-Y just about all marketing of plugs and airfilters etc. is complete bol*&€ks like audio hifi

[@BIGTONY2132001]

@@jagmarc I used Champion Black copper truck plug 4071

[@growingup4487]

at the cost of longevity

[@chrispschultz]

Could you test longevity by supplying constant voltage until failure? You could also supply higher current with constant voltage to shorten duration of test. Be careful though as this could cause explosive and/or other dangerous results

[@blakefelice6625]

I think the real test is on a roots blown application where you're running a cold plug to keep heat out of the cylinder, do any of these fancy materials keep the plug cleaner so the thing still idles without fouling out.

[@garrettw8842]

You'll see a bit more ignition with a larger gap simply due to the larger electrical arc, only problem becomes is if the vehicle's electrical system is up to consistanly output enough voltage and power to spark effectivly. Of course performance applications will be fine, but you're run-of-the-mill coils may not keep up. 👍🏼

[@mariocooldude9092]

This is where the MSD ignition comes in ...the instructions say you can open that gap after installation of the MSD box

[@kleinbottled79]

My other concern would be longevity. Plug might spark well with a large gap while fresh but what about as it ages?

[@SealofPerfection]

@@kleinbottled79 Eventually the gap can get too big for the coil to jump it, but you'd be surprised just how big a gap any electronic ignition can jump. It's huge. It would be a long, long time before it's an issue. Unless you set them to like, .080 to start with.

[@kleinbottled79]

@@SealofPerfection Cool. Good to know. My main take away from all of this is to be less paranoid in general about getting the gap exactly right. Doesn't seem to matter very much.

[@dale116dot7]

@@SealofPerfectionIt can shorten the life of the ignition coil or ignition module/ECM depending on where the actual ‘switch’ is. For racing, no problem, but for those engines that we expect 200,000 miles out of, this is a consideration. The higher voltages stress the insulation in the coil and eventually it breaks down.

[@Harleyforever20]

That was a interesting episode. What I really want to know is what the gains are when you go up or down a heat range AND appropriate tuning adjustments are made. For example, timing and fuel.

[@bradgriffith4231]

Heat range is to keep the plugs clean & has little or no effect on power. Run the coolest heat range without fouling which might allow slightly more ignition timing

[@michaellinner7772]

Considering many of the things you do explain on the show it would make sense to also inform the audience that if you actually showed the entire range from 0-10,000 rpm on the monitor, it would be impossible to see any difference on almost all of your tests no matter what the things you're testing for. I love the show guys. Keep on truckin'!

[@CarsandCats]

I've always ran the Autolites and change them often. A cheap fresh plug is much better then an old expensive one!

[@kellismith4329]

Yep agreed, you leave them in there for 100000 miles you may not get them out - if you change them out more often you get to see what’s goin in inside there

[@Ittybittythetwofacedkitty]

I have to tilt the engine forward to get the back bank (transverse) plugs out so hard to change often

[@Frontpagefab]

It would be interesting to do another test comparing say the top 3 plugs with their racing equivalents to see what effects unshrouding the spark has (if any) and maybe throw in heat ranges as well.

[@bradgriffith4231]

Side gap plugs are racing plugs that unshroud the spark. I modify the ground wire on regular copper plugs to make my own side gap plugs. Works GR8 in my street truck with a 500hp, 409" SBC on 87 octane.

[@FatChanceTheCouchDog]

This video earned +sub. Thank you. 33 yrs working with and being around cars and I'm still learning new and valuable information.

[@SunCityOffroadRecovery]

Don't ever run Bosch. I've seen a ton of em come in the shop missing the center electrode

[@timunderwood4314]

I read a comment about the RAM 5.7. It said that the "copper" plug was required on the older engines. If the newer plugs were substituted, the engine would experience misfires and throw the 0420 code. This isn't the case for newer engines.

[@robertalexander4989]

A bigger gap naturally is going to create a larger flame front because it is igniting more mixture at the instant of ignition

[@jamessmoth8683]

I really wanted to see the results on the e3 plugs

[@dbfcrell8300]

Of course you left out the coolest most real-improvement plug to date: the NGK Ruthenium HX plugs (PSPE for boosted engines and DFE for n/a engines). These are a genuine game changer

[@jamesmedina2062]

What did you find? I found they produce more torque at lower RPM in my boosted Honda

[@dbfcrell8300]

@@jamesmedina2062 I found the same in my n/a engine- more low-end torque along with smoother idle over the oem plugs. While the projected square design is primarily for boosted engines, they work perfectly well in n/a engines too (according to NGK). In my case, even better than the DFE Rutheniums which aren't made for my Toyota engine.

[@realvanman1]

I'm a little surprised that engine builders would not have been familiar with the effect of a wider spark plug gap, so long as you have the ignition system performance to back it up. It seems the longer gap makes a larger spark which ignites a greater quantity of mixture initially, which results in the whole mixture burning sooner / faster, which is better thermodynamically speaking...

[@bradgriffith4231]

This video is nothing new to Engine builders. They learned this decades ago. This video is for the newbies & wanna be's

[@professorginz2379]

David, since way back when we worked at Jacobs you have known (or should have known) that opening up the gap would add some HP and efficiency.

[@michaelovitch]

Opening the gap creates a delay in the spark event,and increases its duration ( more ramp up voltage before spark jump and more travel from electrode to ground) It's like adding ingnition advance and a having a slower spark.,so of course it will make more power. You should try a slower burning fuel with more spark plug gap ,it should increase torque (more longer angular cranck fuel burning time)

[@andoletube]

If the spark is delayed by a wider gap as you say, wouldn't that mean the timing is retarded, not advanced?

[@michaelovitch]

@@andoletube Yes, retarded ,if the spark occurs later because it's longer for the coil to ramp up the voltage to jump a bigger gap. No if the power stroke benefit from a more complete combustion,wich i think is caused by a LONGER combustion process. If you just look at cranck angle,yes it's retarded,if you look from the end of combustion cycle backwards i guess it's advanced As long as the combustion process is longer than the spark event,(it's always the case ,that's why there is advance) it will have a an ignition advance by increasing gap ( from combustion point of view i mean) It's sketchy as explanation,but it's what i think,that's why i speak about a slower burning fuel,it can demonstrate that. They show you something ,but they don't explain it. I try to.

[@Nick_B_Bad]

I’m running a .04 over 390 FE w/Eldebrock Perf RPM heads, cam, intake. Pertronix igniter 3 distributor & coil and I’m running .055 gap with no problem. My only problem is I’m running the Champions that were recommended. I haven’t had good luck cross referencing other brands yet.

[@michaelgreen7028]

Gee…it’s almost like MSD and other ignition companies recommended increasing gap from 0.45 to 0.65 when using their ignition systems…

[@feeneysauto3432]

For ur every day car ur daily driver factory plugs are what you want. Using aftermarket plugs in vehicles made in the past 20+ years can make coils fail, ignition moules fail, cause ghost codes which basiclly means a check engine code comes up like a cam sensor code is super common on older vehicles with wrong plugs but there isnt a problem with the cam sensor its just the plugs.

[@ChinookBear]

I've always ran my plugs on the widest end of the specss.

[@richardelliott8352]

what was shown with the spark plug gap was interesting , and really cries out for an explanation. When I installed the newly specified iridium plugs on C5 corvette, the new specified gap was smaller , and it did smooth my idle minutely . A slight change only noticeable by the sound at idle, and not shown on any instrumentation on the dash.

[@adamarndt7617]

Some of the C5 plugs were running HUGE gaps that were beyond the ability of the ignition coils to light off. More cylinder pressure, more temperature, and more gap requires more voltage to jump the gap. The LS1 ignition coils kinda sucked compared to what exists today.

[@AZFarmFun-hp1cu]

I think the Bosch loses because the origin of the flame front is more offset in the combustion chamber, where the conventional plug sparks closer to the center of the combustion chamber.

[@Woodyvision0420]

The Bosch plug with the dual ground straps was one of the first attempts at increasing plug longevity before things like iridium came out. Like they said, “spark takes the path of least resistance”. When you have two paths you basically doubled the longevity of the plug minus the electrode burning up.

[@bradgriffith4231]

Nothing but a gimmich that's been tried since at least as far back as the 50s. JC Whitney was selling that junk since before I was old enough to get a D.L.

[@petelattimer6808]

the multi earth electrode plugs are designed for extended life. the idea is that they arc across the smallest gap so spreading the wear.

[@shvrdavid]

Actually, they spark wherever the ionization is highest concentration, and it has nothing to do with the gap.

[@jeprerderwererwer56]

When it comes to ignition parts, Beru is the boss !

[@dustinwhite5374]

Ngk v-power I've seen a difference from other brands on the Dyno. Hands down best plug on the market for the money.

[@nobodynoone2500]

Next time, pipette a head with the different plugs. Many raise compression by being further in the cylinder. That would explain the torque difference. An indexing dyno run would also be cool.

[@southerncross3638]

Use autolite double platinums in my 05 GM 3.6 and have had no problems. The ac delco I used before did have problems after 20.000 miles.

[@jeffreyhinman1397]

I’m wondering if the slightly bigger gap essentially changed the timing ever so slightly, therefore creating a horse or two more.

[@davidgalea6113]

They should have tried the plugs that don't have a ground strap...they are used in high end racing...

[@GETLITUP69]

Wider gap is better. Richard Holder tested and verified that 2 or 3 hp is possible.

[@jeffreyhinman1397]

@@GETLITUP69 on an engine that pushes 6-800 hp I’m sure but for a car that has 200-300 doubt you see much change maybe a horse. Also, I’m betting it changed the fuel economy as well.

[@TBPony]

What's strange is my turbo car hates plug gaps, the best plugs for my car are actually gapped .003 below OEM

[@jeffreyhinman1397]

@@TBPony because the pressure blows them out when they’re gapped too much.

[@CadillacZachOffical]

I don't want to sound arrogant but I could have told you that. I learned back during my go cart and racing lawnmower days that a bigger plug gap made better power. The reason for the reccomend gap is to reduce fouling and extend service intervals. I used to run most of my small engine plugs anywhere from 50 to 70 thousandths.

[@not12listen]

In my 20 years of turning wrenches on my own cars, NGK have always been the least reliable. I used to have a Toyota Mr2 and I was able to watch over the span of 2500 miles as the fuel economy would drop. Additionally, as the miles poured on, acceleration (butt dyno) was also diminished. I've tried from their $2 per plug to the $12 per plug, and the results were always the same. I tried basic Autolite plugs and those were decent and reliable. After having grown very weary of this, I switched over to Denso plugs. Not only did the fuel economy stay consistent (better than NGK), but the butt dyno told me that acceleration did not diminish - and that was over 15,000 miles without touching the spark plugs. In my daily driver, NGK is what the manufacturer (Subaru) calls for. And the results were identical to those experience in my Mr2. I switched over to Denso and not only has fuel economy and acceleration remained, but starting is easier, idle is smoother, it has improved (vs NGK) throttle response as well. As per the gap increasing and power increasing, it doesn't surprise me all that much. From my very limited understanding (please correct me if I am mistaken), increasing the gap in a forced induction application is a big 'no no' as you run the risk of the not igniting the air/fuel mixture properly or 'squishing' it. I do NOT know the validity of that.

[@frankpeletz1818]

I prefer standard copper U grove plugs for carbon/cold fouling. I found out years ago dropping the heat range and using non extended tip spark plugs adds torque in a Mopar LA. From a RN 14Y to RN9. Same results on a modified slant 6 going from NGK UR4 to Denso T16RU

[@MP-pz9oe]

Do you recomend opening the autolites from .030 to .065 in a supercharged application ?

[@jkhippie5929]

yeah, but when your running a stocker on points and you dont have the voltage, ...... does it matter then.... is it drastic then ?

[@BrianHoff04]

As a metrologist for 30+ years I have some issues with claimed differences in dyno runs. The only way to say that something made a difference when the differences are so close is to do a statistical study. Repeated runs on each plug with each run being duplicated as much as possible. Then, perhaps, these small differences could be described as real or just common variation. So it remains unclear from this video that a bigger gap had an actual improvement.

[@jagmarc]

nearly 50 yr ago l had a high performing 2 stroke motorcycle that revved to ludicrous RPM. After buying the listed plug brand new and it worked worse than the old one, over several weeks I tried out dozens of different plugs different makes new ones used ones different heat ranges, normal gaps wider gaps smaller gaps..., Every time the best performance highest top speed was a USED plug out of junk drawer it was an L87-Y or something. Never looked back.

[@1967davethewave]

Every old school drag racer I know will side gap their plugs and swear it makes a positive difference. Once side gapped they try and get about a .060 gap or so. One old racer had done an actual test on his bracket race car one night at the fun drags and said he did get about a .04 to .05 decrease in E.T. so he said the claim was supported. I wish they would have side gapped the Autolites to test this theory.

[@mspellman562]

Redo test or add the E3… really wanted to see that

[@astrawally8448]

Biggest variable looked to be the gap in this scenario - why not test the others with smaller and larger gaps (save for the plugs which cannot be gapped) and also gap-less plugs thrown into the mix.

[@jamestone265]

I disagree with the widening angle. I run wider than recommended gap and almost straighten the ground and then rebend it to the gap I want. This usually gives me a level strap and unshrouds the spark….i feel this a better way in helping the burning of the fuel mixture..

[@eag8999]

You didn’t test any silver electrode spark plugs such as Brisk Racing plugs? Their LGS plugs are popular for LS cars and have a 4 post setup. I’d love to see them vs copper (which usually make ~5 more hp than the iridium, etc. that last longer).

[@AutocrossAhole]

would be interesting to see IF there's power differences with different heat ranges. i.e. going with a colder or hotter plug

[@farhadmirzaee4721]

the autolite was hotter and made more power

[@bradgriffith4231]

Simple answer is NO Diffference. Heat range is to keep the plug from fouling.

[@christophergrauer9873]

Hi Guys, There is a channel called PFI Speed they are tuners and they continuously talk about spark plug gapping. I have seen them pick up 80hp just by re-gapping the plugs.

[@DayRider76]

I splurged on a set of msd high pressure plugs once. They lasted three months. I got over five years out of the set of delcos that I replaced them with. I just got my amx running after a long cold winter and three of the ngk's were totally dead? I always seem to find my way back to the old way of thinking, ngk for foreign cars, delco for gm, autolight for ford and champion for the lawn mower.

[@mariocooldude9092]

Yep 👍 heard that same refrain from performance guys

[@kingtut8381]

ON MY 327 FUELIE, A SHORTER GAP IMPROVED THE PONIES ON THE DYNO

[@Twogreenfeet]

original double hump heads?

[@kingtut8381]

THEY WERE FUELIE HEADS. 50 YEARS AGO@@Twogreenfeet

[@mikemustang5488]

I would have really liked to see spark plug indexing explored. Maybe in a future episode?

[@romak4756]

Some people swear by it

[@ryurc3033]

@@romak4756 I definitely understand why it would make a difference driveability wise, having the flame be the same shape in every hole. And it might me more crucial on some engines over others, like a Honda might not care because the spark plug is in the center of the combustion chamber......I never did buy a set of indexing washers. But I've always wanted to.

[@steveconnolly7129]

Make a black mark on open gap end then install,it'll give you an idea where the gap is pointed

[@michaelbullington3182]

indexing threads so that the spark projected toward the exhaust side? Clipping metal back, to gap and expose the spark? Intense and/or multiple spark-ignition upgrade on older setups

[@SpecialAgentJamesAki]

Richard holdener tested that

[@andrewbecker3700]

I've always run Autolites in my cars, and NGK in my motorbikes. The platinum or iridium ones offer increased longevity for cramped engine compartments that make frequent changes a chore.

[@spf-92.5]

Well ngk's are better and the gold standard for plugs. I ran autolites for years with no issues and then ran into some factory dud's that misfired and took a while to trouble shoot. I've seen a few brand new autolite starters and alternators not work out of the box also. It really is a bottom end junk brand, for car parts you want oem, napa, hastings, car quest etc NOT autoshite. Let's not even think about the autolite spark plug wires, they pull apart just looking at them.

[@andrewbecker3700]

@@spf-92.5 Allied Signal is the parent company of Autolite. Recently, many trusted brands have had QC issues and there's been alot of knock offs passing for the real stuff.

[@samuelmcgill-rl3lb]

project farm has a really good spark plug video ,well worth a watch .

[@Boosted0ne]

Thru the years I've heard a lot of cars guys mechanics say plain old Autolites run well. I like NGK run them in everything.

[@yaboykris2118]

Soooo does a larger gap plug work with port fuel injection? Stock ECU? I feel like it wouldn’t. wouldn’t you have to mess with the timing?

[@dgsrks102030]

The factory NGK iridium in my Nissan 5.6 nearing 200k , still no misfires , may end up being a lifetime plug ?